Subsumption game rules, an AI approach to game design

I'm a big robotics fan, and back in the day when I was doing way more robotics than I have time for today I had the good fortune to stumble upon some good reads from Rodney Brooks and learned about the subsumption architecture,
"... a way of decomposing complicated intelligent behaviour into many "simple" behaviour modules, which are in turn organized into layers. Each layer implements a particular goal of the agent, and higher layers are increasingly abstract." 1

It is inherently a bottom-up design that starts with small and simple systems that are incorporated into bigger ones. The small systems become part of a bigger system that emerges through the union of different layers. It is a design mechanism I've been using for Weapons Free. During the first playtests players would ask how I was determining initiative, order of events, etc. I was, as it is commonly said, winging it. I lacked the systems to determine many of the things players are used to in games which are designed in a top-down manner. In these, combat is decomposed into different elements and in turn these elements into their individual black boxes that make up the whole combat mechanics.

Although subsumption and Brooks are common terms in AI based RPGs I haven't found that many references to such an architecture applied to RPG rule designs nor its impact on rule simplification. I'm really interested in seeing where this ends up as I strongly believe a layered rule system would be simpler than a complex flow chart type rule system. Particularly when it comes to complex tasks like combat.

The following diagram show an example subsumption network for a robot. It's pretty easy to see how terms can be replaced to account for protection/cover, movement and attack behavior. In a subsumption system "the main caveat is that separate tasks can suppress (or overrule) inputs or inhibit outputs. This way, the lowest layers can work like fast-adapting mechanisms (e.g. reflexes), while the higher layers work to achieve the overall goal" 2

The higher layers in this architecture hold the more abstract goals: "I attack the orc", "I cast fireball at the goblins", etc. Middle layers handle elements like the actual sword swings or spell casting, on top of the lower layers handling the environment and movement. Attacking and moving are things done concurrently and handled by each layer of the rule system, instead of a fixed sequence of activities done by each character in the party, like a move, casting and attack phase.

This way of assembling the rules poses some problems, but also some great benefits. On the downside there is no clear flowchart to follow and that is something players familiar with initiative-round-robin type rules will find disturbing. Initiative, which sets sequence of events in most games, must be replaced with a means to synchronize concurrent player action. All players in a scene are acting out their higher level activities, and each can be suppressed by their lower layers. The advantage I see is that a great deal many possibilities become available which were blocked out by a more structured flowchart type rule system. Quick reflexes are not commonly handled well in structured flowchart mechanics. If your character moved and is then attacked he can't move again. Why? Because the rules say so even when his instincts would say otherwise. If as player I decide to move and attack and the battlefield changes and my move doesn't seem that wise anymore, there is little I can do. Not because my character wouldn't move, but because the rules say so. All the actions my character could take at that point are blocked, not because my character could or couldn't really do them, but because the rules state something like one move and one action, etc.

In a subsumption system some layers can kick in and quickly change the flow of events. This is possible because they're occurring concurrently instead of being fixed at some point on a flowchart. For example in the game a soldier may raise his rifle and aim to shoot at a target. He may go unnoticed or call attention and get fired upon. The moment he begins to take fire his survival layer makes him take cover even when his intent is to fire the rifle. His higher, more abstract objective to attack is suppressed by the lower more imminent objective of staying alive. This turns game design from creating a series of flow charts describing the combat process in a neat cut way, as would be done in a top-down design, to an assemble of perception rules, notification rules, and activity rules.

Perception rules describe how your character or NPCs for that matter sense and are influenced by their environment: spotting rules, listening rules, etc., in general how the current environment is perceived by the character and turned into decisions by each layer. Notification rules specify how each layer can intercede in the other layers: ducking when taking fire, running when all is clear, etc. Activity rules specify how each activity in turn modifies the environment: casting a spell, firing a weapon, slashing with the sword, speaking, and moving around, among others.

Rules then become an assembly of lower systems that kick in when needed instead of a fixed set of rules described in a flowchart. So far these rules are simpler than their flowchart counterparts. Although I still have many holes in the system, the overall experience that emerges from the interaction of what is already in place is a lot more interesting that what I could have done with a more classic top-down approach to modern combat rules. The rules are more compact and more flexible.



Subsumption image courtesy:

http://www.seattlerobotics.org/encoder/200210/prj4/scrob.htm

1, 2 : http://en.wikipedia.org/wiki/Subsumption_architecture

How much detail is good enough detail?

Looking back at modern warfare RPGs I've played and examining their "detail" got me wondering what's important and what isn't. Is the exact caliber of the gun important? Might be if you have to scavange for ammo. Caseless ammo was a very uncommon item in Twilight2000. Yet it didn't portray any clear tactical advantage I couldn't use in the game to roleplay a scenario. Overall ballistic detail was not adding tactical realism.

More so how do we arrive at such ballistic detail? Through mathematics and models and number crunching that, in the case of simulationist warfare RPG, calculates the bullet trajectory, momentum and impact location.

What does all this work lead to? Does this added detail and workload actually lead to some effect in role playing? When I played Twilight2000 I felt like a submachine gun was just the same as an assault rifle and pretty much like a light machine gun. Sure, there were damage and ammo differences, but when I rolled once to hit with an assault rifle and rolled once to hit with the machine gun it felt all the same. I didn't feel like I was firing a fear inspiring weapon. I always heard it was important to take the machine gunner out first. I wondered why? I felt just about as unimpressive as when using an M-14. A documentary I just saw mentioned that a soldier with a BAR or a machine gun was worth 10 riflemen. I quite didn't feel 10 times more powerful or relevant in an advance on the battlefield than my fellow players. Calculating the exact parabolic trajectory of the machine gun round, finding its exact range and momentum, its impact point and damage, adjusting for recoil, wind, and what not was not making me feel more impressive. I needed something else.

I begun looking elsewhere for detail. I'm designing weapons based not on math, but on experts. Documentaries and people who've used them and told me how they respond. From videos and research I've done on how these weapons are used, their advantages and disadvantages. I'm dialing in the numbers into a program and getting the modifiers I need by a means of regression. I work with these numbers until the weapons feel right.

I strongly believe a game can be simulationist without being "number-crunchinist". There's more to detail than the exact trajectory of the bullet. I've found that a lot of detail and realism can be filled in by the mind itself if simple easy to use models are presented and complemented with other equally important aspects of modern warfare. Fear of being shot at. Responding under pressure. Unknown enemy size and location. Really deadly encounters that require the player to move, cover, relocate and find new strategies. All these are aspects that are sometimes left as an afterthought or enjoy less "detail" or "realism" than the bullets and weapons. Nonetheless the level of detail and realism portrayed by these less glamorous aspects of the game enable or disable a huge set of role playing options for players.

A certain initiative rule, a limit on attacks per round, how a often and quickly a character may move, or simply the need to see a target to resolve combat rolls may change the way the game is played in such a way that makes it much more unrealistic than having an error on the exact range of a weapon.

The bad GM roll, having a TPK day

The GM rolls and the whole party dies. Bummer, that sucks!

My recent post on the lethality in a modern combat RPG stirred some comments and concerns regarding players or GMs rolling poorly and causing player death or even a TPK in a highly lethal game. Is this so? Does high lethality translate directly to high player death? Shouldn't it be a latent game element that leads to a more exciting adventure and becomes more or less evident as a consequence of the dice selected to determine outcomes?

For me die rolls are not in the game to define the fate of the player or party, but rather to introduce a degree of randomness and entropy into the outcome of a single action. The succession of these actions is what seals the fate of the character, not a single roll. I use more than one die in hit rolls to reduce outliner values that may produce extremely bad outcomes. Thus if the character is well trained and the player thinks (hint), lethality should be low, at least for the character. Can't vouch for the bad guys. ;)

Now getting back to dice. When using 2d10 instead of 1d20 the odds of the roll summing 11 (10%) is very different from the odds of summing a 2 (1%). With a d20 the odds of getting a 2 (5%) are the same as an 11 (5%). Thus the odds of getting two successive 2s with a d20 is the same as getting a 2 and a 11 or a 2 and a 20 or two 11s for that matter, 0.25%. With a 2d10 the odds of getting two successive rolls each adding 2 is 0.01%, the odds of getting two successive rolls each adding 11 is 1%. That's a hundredfold difference in favor of things turning out right.

What does this mean in layman's terms? Basically that it takes a succession of highly improbable die rolls to seal a character's fate on die rolls only using 2d10s. If the character is highly trained and prepared, the odds of actually dying are slim. Player decisions become a more relevant factor in determining character fate than the die rolls on behalf of the GM, be them good or bad. Sticking your character's head into a room without proper precautions is going to get you killed more often than a bad roll by the GM.

I've ran games with some players who stay put waiting for that lucky roll or storm rooms without preparation, believing die rolls and hit points will save the character. Wrong. In a real firefight there's sporadic fire, movement, then some more fire, movement, spotting, relocating, fire again, and so on.

Laying behind a log rolling for initiative and then resolving a nice volley of fire, first me, then him, then some more initiative, now him, then me, initiative again, now me killing him and turning my machine gun to his buddy and going over the drill all over again is not how real firefights turn out. Does the expression "sitting duck" ring a bell?

In a real firefight if you sit behind a log firing round after round like that you'll have a lot of "blowing the fuck out of you" going your way real soon. From heavy machine guns to grenades and mortar fire.

In a real firefight the bad guy isn't going to be there, round after round, with his head sticking out nice and dandy just waiting for you to blow it away before he blows your nice and dandy head, that also happens to be sticking out. You're going to be moving, he's going to be moving and it's all going to be a big mess of a fight.

In a highly lethal game as is the case with modern warfare games, tactics, preparation and character training should supersede die rolls. So characters don't actually die. Catastrophic failure should come after either a) player stupidity or b) a succession of bad yet highly improbable die rolls. When failure comes it should be swift and final, to remind players what is at stake.

Players in turn should shift their tactics from rolling high to thinking fast. If the dice will make it less probable to get hit, but if you do you're done for, you might think the odds are in your favor. Think again, recall the part of a whole lot of  "blowing the fuck out of you" that's coming your way if you don't move and keep thinking fast. Take the battle to the enemy, keep him pinned down and move in a whole lot of "blowing the fuck out of them" quicker than they move in a whole lot of "blowing the fuck out of you".

At this point forget about simulationist realism, who cares about the exact trajectory of the bullet when all these interesting dynamics are emerging once characters are no longer pampered behind high hit points and players aren't psyco about scitzo die rolls that may land a 2, 10 or 20 just as easily. When the stakes are high and speed and planning really matter, a great deal of previously ignored or omitted tricks and tactics take a center role.  They now have real application in the game and give the party an upper hand in the game.

Movement reigns as a means to add realism

Putting time to create a simple yet rather detailed weapon mechanism has paid off, but movement is quickly emerging as a means to make the game even more interesting and realistic. Rounds, single actions per round and initiative rolls are yielding to a flexible time frame with a reflex roll mechanism that may yield not only an initiative benefit, but also extra attacks.

Adding detail to the weapons is good, but a player might not know the difference between the game's weapon and a real weapon if he's never fired it for real, and thus not really value the hard work put into obtain such a detailed model or the added math required during the game to make such a weapon feel real. This is even more so for futuristic weapons that don't even exist and thus lack any real life reference point. Now movement, that's something all players can relate to. How a character jumps, runs, turns, swings, stretches out, etc. are all things players can vividly identify with.

When a game forces the character to either take an action or move a great degree of realism is lost. I can't relate that well to a game that doesn't let me shoot as I move, or move, shoot and move again. When I can't run my character past something while swinging left and right, the game looses a great deal of realism.

I'm more forgiving when the weapon range or reach isn't quite right than when I can't do with it what I could clearly do in real life. I can't tightrope walk, nor can I climb walls, but when a character that can do that can't run as he swings his sword... well that's just simply unrealistic as it gets.

What are you thoughts about movement in the games you play? Do you think characters should be given more freedom to move and attack or would that break the game?

Surfing Bird

A-well-a, everybody's heard about the bird Bird, bird, bird, b-bird's the word 

A-well-a, bird, bird, bird, the bird is the word...

Who hasn't watched Stanley Kubrick's Full Metal Jacket and just loved the Surfing Bird scene? God I just love it. For those who haven't seen it and for those who love it as much as I do, here it is again.

Damn I love that grin as he sees they've gone down, but I digress, this is not what I want to talk about. I want to look at why the first group of VCs pass unscratched and the second is hit. Well it's clear enough that he was reloading while the first group passed, but was he the only one in the whole platoon looking that way? If not so, why didn't anybody else fire? Did they not see them in time?

This scene has been spinning in my head for a few weeks now as I try to resolve a way to portray split second reactions in the game. Who aims first? Who fires first? Conventional theory says that's initiative, but initiative is sometimes too random, it involves the whole party and it generally dictates order and not necessarily advantage when it comes to many split second actions. Particularly an advantage that strongly leverages character training.

What do I mean with the last point? Well conventional initiative says the VC move first then the Marine fires or vice versa. If initiative rolls matched they'd be caught as they run, but otherwise the Marine would have nothing to shoot at or they'd pass unscratched as the first group did. But what if he wasn't aiming just there and then? What about spotting them with the corner of his eye and then turning, aiming and shooting?

To solve those split second reaction times, setting a sense of order and at the same time an advantage in time I'm introducing a time frame called a beat. A beat doesn't specifically last a second or for that matter a fixed amount of time, it's more of an abstract response advantage. Beats are a measure of how well a character made a reflex check, which is basically an attribute check modified by skills. For every four points a character wins he earns a beat which equates to a short action. For example if a character earns a whole beat he may fire his gun twice during the span of the action. If two enemies are involved and they roll 2 and 4 while the character rolls 8, the character may discharge his weapon twice ( has a whole beat lead on the fastest enemy). The character fires once, then a beat goes by and the counter drops to 4, the enemy who rolled 4 fires, but also the character as he earned a beat ( 8 - 4, a beat = 4 again). They fire simultaneously and finally the enemy with the 2 roll fires.

By leveraging the character's skill in the roll as well as the character's attributes the roll means more than just simply who goes first. It is strongly weighted for the well trained party members and it gives a clear and distinctive value to training. Making well trained characters ever so lethal and more prone to survive in high risk situations.

Drawing guns

It was bound to occur soon and I had a rule that worked pretty well. Draw and aim speed became a concern in last nights game.

The first sniper team had just left the building through the window with the prisoner at hand. The second team stayed in the room to cover the entrance. Then the dreaded cling clang of a grenade being dropped into the room followed by the flashbang that blinded and disoriented the team in the room.

The Marine spotter outside turned back to the window and aimed inside as the Spetsnaz rushed in to finish of the team in the room. In a heart stopping roll the player rolled low enough to not only win, but take a two action advantage on the Spetsnaz. Before any could fire on the stunned Marines the spotter had put a shot into each Russian. One went down the other was saved by his vest. Her moved right and turned to shot at the Marine in the window. A bullet scraped the windowsill barely missing the Marines head. The Marine fired back barely injuring the Spetsnaz who in turned fired back hitting the Marine in the helmet and causing a painful, but non lethal wound. The Marine fell back and the call for "medic!!!" was heard.

The Russian quickly turned his attention to what was his prime objective, the team already in the room. Too late, the team´s spotter had gotten enough of his wits back to aim. The Spetsnaz faced the blazing barrel of an M4 as he was crushed against the wall by its rounds.

The rule is simple, you need to row low below your attribute score. The lower you roll the better, and the score can be modified up by the character's skill with the weapon. Making the character even more prone to win by a large margin. For every four points or "beats" the character rolls below this score an action is granted to the player. The Marine won by 8 versus the Spetznas' 4 and 2. This gave the Marine one extra shot before any one of the Russians could fire. He shot the Russian who rolled the 4 first and kill him. Four "beats later" it was the Russian's turn with a roll of 4, but he was already dead. Tough shit comrade. So the Marine fired again against the slowest of them with the 2. Hitting him he drew attention from the stunned team to himself, and the rest, as they say, is history.

Image source
http://blogs.reuters.com/photographers-blog/2013/07/26/the-gunfighters/

The cloak of balance

Rule induced balance in a game is a cloak that hides entire sets of options and possibilities from players. This is a lesson learned from this month's playtest sessions. It is possible to survive a highly lethal game without the need for "balance rules" that make for a fair game.
Granting every player an opportunity to participate in the game is important. Balancing stage time is important so no one get bored. Enforcing such a thing through a set of rules mean to balance character strength and even pamper the character from the perils of the adventure is a very risky thing.
I find it risky because it creates playing habits that block out entire options from gameplay. Certain actions, strategies and activities are simply not done because the rules for balance don't promote them or worse yet, hinder them.
Such has been my experience with things like fixed attacks per round, deciding to move or attack, initiative rolls and hit points. I've granted many attacks per round to characters even as they run around, made round duration a rather variable value, done away with initiative and fixed hit points at a very low level. Yet characters are not dropping dead like flies and no player is left out of the action.
On the contrary, a lot of new dynamics have emerged. Players have done things that were not common in my games before because I was playing bound by a set of "balance rules" that were "cloaking" all these options from the players. Now characters may die at any moment, but they're more alive than they've ever been.

Fighting on a bad stomach, being ill in a dungeon.

Had a bad day yesterday, my stomach was killing me. Fortunately it wasn't Moctezuma's revenge, but I did feel terrible. Some food poisoning from something I ate for breakfast.

This got me thinking how often do characters in your campaigns get sick. It is possible to carry iron rations for a week or two, but water? Where do characters get water in a dungeon or wilderness area? How do they purify it? How does this affect your cleric spell list?

Hunting for food and not cooking it properly can pose a whole set of risks to the character's health. From short term infection to long term parasites. Have you taken into consideration these aspects in your campaign?

If you do, how do they relate to game mechanics, hit points, health, spell casting abilities and combat?

Not cutting down on lethality in a tabletop RPG

Character death is not something well seen in RPGs, nobody wants to drop out of the session because his or her character died. Yet it is tough to roleplay a modern warfare game, specially one centered around black ops, without considering that your character won't make it back. Worse yet, that he or she can't make it back or must not make it back.

When the mission is more important than the soldier is your roleplaying more important than your character?

Making things extremely lethal has not only opened the doors for new ways to resolve combat and make encounters survivable through skill and tactics. High lethality is also opening the door to new aspects of roleplay which are more realistic and seldom explored by many. So far it has added a greater importance to planning, speed and resolve over everything else. Retreat, cover and redeployment have become common place when previously stand and deliver strategies were used, legacy of some other less lethal games. Now comes the question of paying the ultimate price. Are players up to the task?

Had an interesting conversation last night with +Jonathan Henry and +Keith Bailey and Jonathan brought up the issue of the obligation to complete the mission. Will players sacrifice their character for the benefit of other player's characters? Will the do so for the mission? Will all players sacrifice their characters if that is what it takes to succeed?

If so, how does this affect character development? Would you as a player invest lots of time in developing a character that might not make it through the first session? Wouldn't this make the game an eternal succession of one shots?.

Now lets draw a line between overdeveloping a character and delaying the "getting down to play" vs overdeveloping a character that may die soon. I don't want to delay the game, and that is not where my question is going. The character may not die, living on for many more sessions only to arrive at this one moment when they all must die to succeed. Would your investment in your character stop you from succeeding in the mission? Would you sit down and play again?

It's not the weapon it's the soldier, making skills matter

Crossbows came first. They open the way for easy killing power to the common peasant. Suddenly it was easy to train a soldier to kill a knight. Such was the fear of the crossbow by the church and nobles that it was banned many times. The common peasant could stand up and kill a knight in full armor with one shot. Whereas bows required great upper body strength, skill and training to operate effectively the crossbow could be trained in weeks if not days and used by a common peasant to kill a knight.

The trend didn't stop there. Firearms quickly became popular for the same exact reason. It is relatively easy to pick up a gun and use it to kill. If it's so easy to use, what's the value of skill and training? Aside from issues like weapon cleaning and upkeep, there has to be some value when it comes to combat, what is it? This of course is a rhetorical question. It is clear that skill in firearm use is a must. While shooting someone at short range can be easy, doing so at longer ranges can get complicated. The real question is: How to represent this in a realistic way? By realistic I mean a way that means something substantial in the game at the right moment.

This has concerned me ever since I started writing up the combat rules for the game. Linear probability distributions don't work to well with this. Every + 1 is the same probability increase no matter what. It's all 5%. Change to d100, each plus is still the same 1% increase. A - 5 for range can be countered by a + 5 for skill. This + 5 is a good bonus. But someone with a + 2 almost cut that benefit in half. How long did it take to train to have a + 5 and how long did it take to train a + 2? Is it fair? Probably the shooter with the + 2 just trained a few weeks and the one with + 5 months of not years. Now lets consider point blank range, + 0 modifier. Can we honestly say the expert shooter with the + 5 bonus is safer than the one with the + 2? Are the odds of missing at point blank so off that those bonuses would actually matter? Honestly I don't think so. They're both in a load of trouble at point blank range.

So to make skill matter what I'm using now is a bell shaped distribution. One in which the end point values add little benefit to the odds for each skill bonus. Range and weapon quality put you some point along the line. Point blank places you at the top most values where each + 1 from training counts very little towards increasing your odds. Facing off an untrained shooter will not be that much easier than a trained one. There is a very low probability of missing and you're in a load of trouble no matter how good you are.

Things become interesting when you begin to put some distance between you and your target. The range places you on the part of the curve with greater slope. Now skill begins to matter. Each + 1 means a much bigger increase in the odds of hitting than at point blank range.  Suddenly the + 5 means a whole lot more than + 2 and the better shooter has higher odds of hitting its target, by a long shot, than the lesser trained one.

Finally there is long and extreme ranges. Targets so far that shots are impossible unless specialized equipment (rifles and scopes) are used to take the shot. Unskilled users will have practically no possibility of scoring a hit. Skilled users, those trained in the use of the rifle and scope, will be able to benefit from the bonuses these pieces of equipment give. Yet these bonuses are just enough to put the shot at the beginning of the distribution curve. Just as it begins to slope. Good skills will count, but not enough to ensure a high hit rate. Excellent skills, those acquired after months of training and years of experience are needed to get those high odds to hit required for a one shot one kill.

100% precision

How comfortable are you with shots that can't miss? How about cumulative bonuses that add up round after round to arrive at 100% precision, or so close characters won't miss? How about impossible shots that become possible after such bonuses are added?

When using machine gun fire tracer bullets can be used to walk the weapon to its target. You literally can't miss. The downside is that this requires time and leaves a bright red line leading straight to your position.

I haven't seen many rules that allow for bonus "to hit" to add up miss after miss, but it does make sense not only for machine gun fire with tracer bullets, but also for sniper fire and even melee combat. Every miss and for that matter every hit could mean a learning and adaptation process that makes the attacker better.

When Corporal Craig Harrison (UK) took his record breaking 2475m kill (2009, Afghanistan) it was by no means a one shot one kill attack. He was way beyond the effective range of his weapon, but his spotter kept adjusting based on prior bullet impact positions. This allowed Harrison to zero in on the target until he took the machine gunner out. This was a slow lengthily process that put his unit in peril.

After the first MG operator was taken out another enemy soldier took the MG and started firing again only to be taken down by Harrison's next shot. After all Harrison had already zeroed in on the target and the second attacker was dumb enough to start shooting from the same exact position. So not only was the "bonus" applicable to the hitting shot, it was also applicable to all following shots as long as the enemy didn't change position or for that matter tactics.

What would the effect on gameplay be if players could keep adding and adding more bonuses as they keep missing? Making impossible hits possible? If each gun shot allowed for bonus for the next roll. If each machine gun strafe allowed for a bonus in the next strafe. If each miss on an armored knight allowed a plus on the next attack as the attacker becomes better at predicting the defenders movement.

For this to work well lethality must be a big concern and time of primordial essence. There's an urgency to getting that shot placed and those bonuses, round after round, are paid at a very high price. The price of getting dead from incoming fire or melee attacks for that matter. The rule could be left open to allow bonuses to grow and grow. With low hit points and high lethality there's little odds of getting to +5. Your character will probably be dead before missing so much, or as was the case with Harrison his unit would have been overrun and killed if he kept missing.

Massive weapon fire in RPGs

Watched Act of Valor this weekend. It was a 6 hour bus ride to Guadalajara so I had time to watch it and watch it again. I was enthralled by the boat(SWCC) ambush scene when the team is trying to escape on a truck. The ditch it into the river just as the SWCCs turn the river bend and open fire with amazing force against the pursuing forces. I watched over and over again trying to get the feeling of it and transpose that into the game without going crazy with die rolls.


The idea is to create a simple mechanism to represent weapons shooting in excess of 2000 round per minute. The SWCC has:

The GAU-17/A is a variant of the M134 7.62mmx51mm Minigun. Six rotating barrels and an electrically-powered feed system, the GAU-17/A is capable of up to 4000 rounds-per-minute and is a great area weapon used to suppress enemy fire in the case of needing to buy a few minutes of time during a Hot extract.

The Browning M2 is an air cooled, belt fed machine gun. The M2 fires from the closed bolt position. The M2 fires the .50 BMG cartridge, which offers a max effective range of 2000 yards, accuracy and an excellent fire suppression weapon at 1200 Rounds Per Minute.

The M60 is a gas operated, air cooled, belt-fed, automatic machine gun that fires from the open-bolt position and is chambered for the 7.62 mm cartridge.  It has a max effective range of 1000 yards at ~2800 feet per second

Mk19 Automatic Grenade Launcher. The primary ammunition for Mk 19 is the high explosive dual-purpose M430 grenade. Upon impact, the grenade can kill anyone within the radius of five meters, and wound them within the radius of 15 meters.

Source: http://sofrep.com/swcc/weapons-gear/#ixzz2dH73p4YS


So far I have worked with just the M249 and a 50 cal mounted on HUMVEEs. But seeing the amazing firepower GAU got me wanting to put it into play, but a bit more than just waiving it as some suppression rule and without going crazy with die rolling. Here's a clip of the scene so you get an idea what I'm talking about.

And another nice video from the Navy showing the craft in action.

Using massive fire power in tabletop RPGs can be a daunting task given that hits are determined by die rolls. At 4000 rounds per minute and ten seconds to the combat round, that's 666 die rolls for all those bullets (what a nice round number that gives [grin]). As appealing as rolling 666 times may sound it is just out of the question in a real game. I'm using a single roll for the attacker and an additional roll for every target to determine suppression, hits and effects of cover.

To do so I'm taking a more statistical approach to the mechanism based on bullet coverage, rate of fire and affected area. The intent is to suppress first, kill later. No one in their right mind will stand up in such a hailstorm of bullets, but they still keep firing, why? To keep them pinned. If someone brave enough or stupid enough were to stick his head out to shoot I want to determine the odds of getting hit. I also want realistic odds of getting hit from the initial surprise attack.

So boat comes in, opens fire, kills as many as possible while the surprise factor is on and enemies are exposed. As enemies take cover they become harder to hit, but not harder to suppress. They will still be forced to tuck in and cover. If someone where to sneak out and try to return fire I want some odds of getting hit, not a simple "surprise, you're dead".

The following table shows the odds for different rates of fire for different area sizes. I'm working on two sizes 10m and 5m, meaning the weapon is continuously swept over either a 10 meter or 5 meter area where enemies are believed to be.

			Odds of body impact
Type of Fire	Odds of hit	Odd for suppression	100% exposed	50% exposed	10% exposed
MG Fire into 10m area 100 RPM	35.47%	66.79%	35.47%	28.27%	9.99%
MG Fire into 10m area 200 RPM	57.53%	81.39%	57.53%	47.04%	9.99%
MG Fire into 10m area 500 RPM	74.76%	95.16%	74.76%	57.53%	16.57%
MG Fire into 10m area 1000 RPM	90.86%	99.11%	90.86%	70.94%	16.57%
MG Fire into 10m area 2000 RPM	97.03%	99.99%	97.03%	78.24%	23.03%
MG Fire into 10m area 5000 RPM	99.38%	100.00%	99.38%	86.72%	23.03%
MG Fire into 5m area 100 RPM	66.79%	86.72%	66.79%	52.43%	16.57%
MG Fire into 5m area 200 RPM	90.86%	97.73%	90.86%	70.94%	16.57%
MG Fire into 5m area 500 RPM	99.59%	100.00%	99.59%	86.72%	23.03%
MG Fire into 5m area 1000 RPM	99.99%	100.00%	99.99%	92.52%	29.34%
MG Fire into 5m area 2000 RPM	100.00%	100.00%	100.00%	97.03%	35.47%
MG Fire into 5m area 5000 RPM	100.00%	100.00%	100.00%	98.75%	35.47%

Odds of hit : the odds of hitting a human size target standing in the area.
Odds of suppression : the odds of any target (under cover or not) of being suppressed and wanting to take and keep cover above any other action.
Odds of body impact : odds of taking a hit given a certain amount of cover. At 100% exposure odds are the same as odds to hit.

As you can see at 4000 rounds per minute the GAU has high odds of taking anything standing in its line of fire that isn't behind solid cover. Popping out to take a shot back at the enemy still gives the GAU high odds of scoring a hit (23 and 36 % depending on size of affected area). Suppression will be great for any weapon firing 500 or more rounds into the area. This will require skill and training to overcome and be able to return fire. To do this the enemy may pop up, aim and shoot, giving more time for the GAU to blow his brains out or simply stick the weapon out and fire blindly at the target.

Those will be covered in the next post related to blind shooting into an area.

Weapons Free is a modern day warfare RPG I'm currently developing. You can join the community to follow on its progress and join playtest sessions.

Join Weapons Free Community!

Does age affect your game designs?

How does your age affect the games you design? And in what way?

For me there's experience with older RPGs, the more classic ones. This tends to shape your view on RPGs, as with everything else in life. The first things you meet, specially when young, leave a longer lasting impression. Younger players are exposed to many more rule systems than I ever was in my highschool years.

Secondly with age comes a greater value for time, or simply less of it to put into gaming. Much less so game design. In my case I could no longer digest the endless tomes of books I used to read in highschool. So not only do I lack the time to write endless collections of books, even if I did have the time, I wouldn't do it. I simply can't burden someone else with something I personally wouldn't do myself. So no long rulebooks either.

Do you think your age affects the games you design? If so how and if you were younger or older what would change?

Initiative rolls as to hit modifiers

A lone soldier is walking through the jungle, suddenly he stumbles upon a patrol of enemy soldiers. He has his sidearm in hand and another revolver holstered. The enemy has assault rifles strung from their shoulders. Conventional RPG wisdom would call for a die roll to see who shoots first. Whoever wins gets the first shot and if it's a hit there is a high probability of taking out the target and not being affected by return fire.

The truth though is that unless the shot severs the spinal cord at the base of the head they will all get return fire regardless of initiative roll. On top of this both parties are in a rush to get their shots off. Conventional RPG wisdom dictates that once the initiative is won the shot is a controlled and aimed one. Not really a hasty shot meant to incapacitate and stop an enemy with a weapon already drawn at oneself.

Let's break down the "initiative phase" into its constituent components.

• Realization the enemy is there, overcoming the surprise and reacting to it.
• Drawing/raising the weapon to a shooting position.
• Discharging the weapon.

Now instead of one initiative roll to see who does all this first lets think for a moment that both parties are startled by the encounter. They quickly recover their wits and respond to this. The real difference isn't in how quickly they respond as they're doing it at practically the same instant. Once again, the response is so close to each other that unless the "first" shot hits the head and stops the brain's signal from reaching the finger, the trigger will fire. So figuring who shoots first is pointless since any hit will be lethal yet not fast enough to stop a response. Aim not initiative is the factor here.

The key is coolness and how well the character can aim when all his instincts are telling him to turn and run. We can apply an initiative roll, but whoever wins gets the difference between his roll and the enemy roll added to the to hit roll. The winner of the "initiative" has better aim. Shots will be fired simultaneously, but there's a higher odd for survival on the part of the "cooler" character.

Thoughts? Have you ever roleplayed a shootout in which the initiative roll took the excitement out of the encounter?

Multiple characters per player

A quick and dirty solution to the high lethality in my modern warfare game is simply to increase the amount of characters per player. Now let me be clear. The character's skill and training should be enough to give a good fighting chance, but let's face it with grenades flying around, mortar rounds dropping from the sky and machine guns spitting 1000 rounds a minute something is bound to go wrong and I don't want a player to be kicked out of all the remaining fun. Specially payback fun for killing one of his or her characters. (grin)

I initially took the idea of a squad per player from DCC's funnel, but have since come to see other benefits, albeit with some drawbacks. When players have whole squad under their control the characters are more coordinated as to what they do in the game. More like real life.

Usually players don't train together day in and day out. So getting them to coordinate four characters in a game is hard. Which comes to explain the lengthily hours of combat as players take minutes to figure out how to enter a room, kill the rats and take the copper. When one player controls four characters all this unnecessary chit chat doesn't occur. The characters act more like a team and their skills stack up adding to even more survivability. Which brings me to the first question. "What slows down game, too many players or too many characters? Personally I haven't see too much of a slow down with three players managing twelve characters.

A concern I do have is that characters may not mature and be developed as much is a player controls more than one. With one I tend to cherish it, develop it's personality, and flesh it out over time. With many this might get a bit harder. Creating and role playing four different personalities at the same time can be tiresome and may lead to similar characters if the player isn't in the right mind set just then. Thoughts? Can you manage different personalities as you play with many characters at the same time?


Photo credit

Nick Jensen
http://www.flickr.com/photos/45272606@N02/8307027081/in/photolist-dE4FJR-8eLXva-96YtRr-7RE7Ks-cSwg6q-7Lahfe-9fE82y-9EyYej-7NNDqA-fxi87b-bkmsnu-c927uj-7Zgx7s-d7K1Cw-7YH6Da-876Nai-epPDDA-9wTrHe-7KbN7d-7RBgUt-bvit9h-evw14g-8P8ayT-9v7WYm-ekVVqs-8SU1k3-986RDD-86HThC-7CxBQG-dd6uAz-dd6w73-dd6udc-dd6ufB-dd6xdo-dd6umt-dd6wam-dd6vF1-dd6v4X-dd6uRr-dd6vQS-bMLwb2-9WvZg4-drQMAo-drQMBb-9radyV-aPtm5a-aPtfdc-dwJedV-94zqs1-fcWQcQ-7P5dRc

What's his status?, He's dead sir, Bennet is dead.

After clearing the second building of Spetsnaz and taking three prisoners the team discovered an underground tunnel that lead to the building from which a truck had escaped a few minutes ago. Concluding this vehicle could be carrying the weapon the put the Predator drone to follow it. Sure enough it had a crate and it was headed to the lake's shore. With little time to waste the team saddled up and rode the HUMVEEs bath through the town in an attempt to give chase to the runaway weapon.

The drive through town was a lot harder than than the previous one getting in, reminiscent of Blackhawk Down's convoy scene. The town was way more awake and ready to engage them this time. In spite of their massive firepower PFC. Bennet took one to the head while manning the 40 mil cannon, fell to the HUMVEE's floor and bled out before he could be assisted.  Reed "Hawk", the second sniper team's spotter took the gunner's position and finished off the attackers. Heavy fire was still encountered as they drove the last few hundred meters out of town and onto the surrounding hill sides.

This part of the mission ends with 48 locals dead, 8 Spetsnaz killed, 2 prisoners and 2 KIA (Bennet and Butler). The weapon is still at large somewhere in the Iranian desert. A buyer, a purpose and destination still needs to be found for it. Our next session will take the party undercover into the heart of Iran to search for the contact to whom this weapon will be delivered to.

When failure is not an option, stacking skill bonuses

There are some jobs in which failure is simply not an option. Players have to be able to succeed at all costs. To encounter challenges in a game in which failure means more than TPK (see image bellow), means players must have a high, almost certain, success rate. On the other hand if success is assured where is the challenge in the adventure? If success is a sure thing because failure is so catastrophic, doesn't the game just become a story in which the GM just narrates the outcome of one success after another?

Or is there a way to stack bonuses so skill checks are quite certain to succeed while still having that little margin for error that makes your heart skip a beat when you roll the dice?

I'm working on some skill mechanics to allow for characters to add their skill bonuses to a task, work together and make success almost certain. That almost might seem like too certain a success rate, until you see what's at stake if you fail (once again see image at left).



So here are some ideas to make this work:

• Die roll with a lot of steps, like d100 vs d20 which has only one fifth as many.
• Diminishing returns which means a bell shape distribution.
• Characters can stack their skill bonuses and attribute bonuses to the roll. There will still be a chance of failure given the diminishing returns.

Things I want this to work for:

Cut the blue wire

Weapon disarming in Weapons Free may be a very common task. Having help from an external source may add bonuses to your explosive skill check. Failure to cut the right wire or follow the proper disarming procedure can be quite catastrophic.

Identify agent

Someone is ill, what biological agent is it? Running some tests in a team of medics should add bonuses to solving the issue quicker. Failure to isolate the pathogen and find a way to stop its propagation can be quite catastrophic. Even if just confined to the unit in the adventure it would still be a game stopper.

Close quarter combat
The odds of putting a bullet in a target should be astronomically high at close quarter range, but drop off drastically as range increases. Skill should play a strong role here. At longer ranges bonuses from equipment like scopes should add up to make long range shots easy for those trained in their usage. Failure to be the first to hit its target when entering a room can be quite painful for the character that fails to take the target out.

Thoughts? How many games have you played that allow many characters to chip in on a die roll to increase their odds while still keeping a margin for error that makes the game exciting?

Image sources

http://gizmodo.com/5867017/taking-apart-nukes-is-probably-a-stressful-job

http://www.rpgpost.com/topic/15232-inspiration-strikes-21/

Tactical Nightmare Dungeon

Damn, I've got to use this in my next mission! This is an Afgan village in a hill, not on, in it! A modern day dungeon crawl in the making. Got this cool add on for Campaign Cartographer so I can create isometric dungeons. I figure it's the only way to represent something like this.
Just imagine trying to put this on many layers and then switch between pages in Roll20. It would be a nightmare that would turn combat into a crawl.
I'll work this weekend on something and post it on my next map blog. I guess I'll have to do the interiors with the isometric icons and then do some touch up work with the GIMP to add exterior detail and indicate what is outside and what is inside. If all goes well I'll be able to run a session with this map in two weeks time.

Laser bullets

We're all used to energy clips and laser rifles as standard scifi weapons. When the energy clip runs out one that fully charged is put back in its place. But what if instead of energy clips conventional clips with laser bullets are used? The bullet being a one time charge for a blast.

Imagine a much simpler, chemical based laser blaster that uses bullets to power each blast. There are no electronic components which may be susceptible to EMPs. The bullet is triggered and a reaction takes place inside that powers the laser device. Once used, the casing is expelled and another one put in to fire the next laser blast. The chemical could be something characters could carry in a pack and could reload the casings with.

Thoughts?

Full campaign on!

Last night I ran the first full blown Weapons Free campaign session with +Kaan Emirler +Gabriel Perez Gallardi +Tre' Grisby  and +Brian Kelsay. They're on a broken arrow mission and must recover the weapon's core before it falls into the wrong hands. They crossed the Iranian border and entered a small village to recover it by quickly deploying support teams in the south and storming the building. Brian did a great job at clearing the south building, but the weapon wasn't there!!! So Kaan picked up the assault team with the HUMVEEs and drove them over the light blue line to the other suspect building, the north one.

This was not a welcomed move by the locals who attacked the convoy turned the scene into something taken from Blackhawk Down, the convoy scenes. Kaan and Brian had to put some heavy 50 cal and 40mm canon fire into the building to suppress the enemy while they drove by. Meanwhile Tre and Gabriel were giving support fire with the MG and sniper rifles.

As they arrived on the north end of town they positioned the HUMVEEs behind some walls and moved in on foot after popping smoke in the area. Gabriel took some targets out who ventured on the roof and Tre gave relentless MG fire into the southern wall. Meanwhile Gabriel's second sniper team moved to reposition itself on the north western side. Kaan gave support from the HUMVEEs as Brian moved in to raid the building. To his surprise the occupants of the building were not some simple thieves and smugglers, they were well trained SPETSNAZ. They weren't dropping as easily as the unarmored men encountered in the southern building. Held back by the increased thread the team pulled out and began looking for another entry point. As they were going around some men on a pickup with a 82mm B-10 recoiless rifle stormed out the building and attempted to escape. The team is putting some fire into the pickup in an attempt to stop it before it escapes. The session ended as the south team notices another vehicle leaving from the eastern building, at full speed and into the night. Who's who and who carries the warhead? We'll settle that in the next session.

Here's live footage from the mission. Kaan's characters laying down some serious fire on the SPETSNAZ infested building as Brian's men try to storm in. You can make out the gun purring and the cannon going tuk tuk tuk.

Perfection is the enemy of usefulness

So Numenera is out and from what I'm reading it's a really good yet imperfect product, with typos and other observations about setting and rules being made. But it is here and now and it is useful. Meanwhile Monte's old employer is still questing for the perfect RPG balance while trying to push something out the door and someone with a very active Facebook account is still figuring out how to start writing the rules for the perfect dwarven game.

What's happening to the others? Feature creep? Baggage from the past? Trying to please everyone while pleasing no one? Inexperienced publisher? Why is Monte out with his game and the others not? Now from what I've been reading about the rules( I don't have the book so I'm going by word of mouth) the game has its caveats depending on who you read. It is d20 based with a whole set of new terms. Some easy mechanics and some different goals, like no XP for killing creatures. It seems a bit like a step in some odd direction coupled with some "bad strategies" like new terms players don't know that may lead up to steeper learning curves and slower acceptance. There are some things that seem incomplete, not fully tested or maybe unbalanced, or maybe it's just misinformation from my lack of the full document. Either way, in spite of its imperfections,  it's a wonderful piece of work which is creating a whole new phenomenon from what was originally meant to be just one book, and it's here now.

This reminds me of Pablo Picasso's words "Every act of creation is first and act of destruction". I see in Monte's work a big step from what was being done, a destruction of the old and the creation of the foundations for the new. Is it perfect?  I doubt it, but it is here now, on time and scarcely a year after work started on it. It promises to get the job done beautifully, it is useful and practical and opens up the door to an exciting new setting. I honestly prefer to have an useful item today than a perfect one tomorrow. I'm  excited to see where this project goes from here. What will all the things that were left undone, unpolished and unfinished transform themselves? I'm sure Monte left lots of stuff out to finish on time and he will treat us to some surprises from that. I'm also excited about having a live product that will evolve and provide newer things. The true downside for me is I'll have to wait two weeks to get my copy. Patience.

Let's Rock!

This is one of my personal favorite scenes from all movies. The moment when the Colonial Marines realize they're something really bad around them. Vazquez screams "Let's rock!" and lights the aliens up with her MG. So bad ass!!!





Here's a short 9 second clip from the movie.

Now try replaying this in a modern RPG.

"Let's rock!"

Roll for initiative, and most surely lose. I mean they're fucking aliens, did you see how fast they move?

Ok, we'll grant the element of surprise and let your character shoot first.

Great, I fire at the first one. 

Wait you can't see it.

So I shoot wild.

Uh, the rules don't have a clear way to resolve this. So I could add a modifier to your roll or ok, lets say you see one over here.

Ok, I shoot at it.

Ok roll for attack.

Rolled an 8, you missed.

WTF, how can I miss, did you see the fire power in that thing?

Yes, but you miss.

Ok I attack again.

Rolled 18, you hit.

Great!

Roll for damage, it's a big round 1d12

Ok, (rolls), got a 3.

Barely scratched the alien.

WTF? It's an explosive 10mm round, what the fuck are you talking about.

Ok, sorry forgot that. Round explodes and delivers an extra d12 of damage

Ok, (rolls), got an 11.

Ok, (GM mumbles to himself about HD and HP), ok it took 14 points of damage and it's still standing.

Ok I shoot at it again.

Uh, sorry you only have two attacks per round, it's the aliens turn, all 12 of them.

Fuck!! What? I run out of there.

You can't you've already attacked twice,  you can't move.

Fuck, fuck and triple fuck. We're fucked.

Now take initiative away and replace it with coolness, remove the limit on attacks per round, allow for moves and attacks and include massive fire rules.

"Let's rock!"

I fire the MG into this 10m area of the building hitting whatever is hiding in the walls.

Ok, roll 2d20 to hit.

Got a 24

Ok, (GM rolls secretly for the aliens, odds of the MG hitting at that range is 65%, 7 of the 11 aliens get hit, GM rolls secretly for damage 3d6 yielding results in the order of 9 to 12 for each round plus explosive damage.)

You hear a lot of squeals as some sort of creature is getting hammered in the tunnel. They're many, some drop to the ground wounded, but others keep coming on the walls and roof.

I begin retreating as I put more fire into the area.

See the difference? This is the type of game mechanic I'm looking for in Weapons Free. More realism by a different set of rules that open up the options for players without breaking the balance.

Thoughts?

Bonuses for MY sword

Not bonuses for any sword, I mean the sword my character has grown up with, trained his whole life. The one he went to war with as a lad.

The sword isn't of great quality. It isn't magical either, but the character has grown up with it. It's an extension of the character's arm. Isn't this worth a bonus?

Maybe a bonus to initiative as it's second nature to use the sword. Maybe to hit as it's a seamless extension of the characters body. How about a bonus to parry as an AC benefit? Or an extra attack due to the ease of use?

Have you given bonuses to weapons like this one? If so what type of bonus?