Saturday, November 30, 2013

Scenes, rounds, beats and tics, narrating modern warfare in Weapons Free

So far I had mostly winged turns in Weapons Free, narrating as things unfolded and doing my best when things got down to split second reactions. Now I've playtested what seems to be the final time frame for action sequencing. Instead of a fixed round based system with initiative rolls setting the order of events I'll be having four time frames: scenes, rounds beats and tics. Each cover decreasing frames of time. The only one with a fixed length is a round which lasts 10 seconds.

The Scene

A scene is an episode in the game session in which related events occur. These events can be free form narrative or a round by round succession of events. This depends on the story's need for precision.

The scene time frame example

A group of eight Marines are taking on a building. They are split into two groups of four, each entering from opposing sides. Four of the Marines on the near side have just taken out a Spetsnaz lieutenant and captured his captain. Two take the prisoner out through a window as the other two cover their escape. So far a minute or two have elapsed since they cuffed the captain. A flashbang grenade is dropped into the room shortly after the first two Marines leave the room through the window with the prisoner An encounter is about to begin and combat will require a smaller time frame to resolve. Game drops to rounds for the four characters involved while other four Marines located at the far side of the building remain at scene detail.

The round

A round is a ten second time frame in which actions are taken. Characters have a certain limit to the amount of actions which is set by fatigue rules and just plain GM and player common sense. Fatigue limits how many actions may be taken in a 10 second time frame. Common sense helps in not having to use the rules every single round and keep them as a reference for truly extreme situations. Events are not limited by the end of the round, only resources are replenished and ammo kept track of. A round may go by without a single initiative roll (called reflex roll) or fast paced rounds may call for many reflex rolls. That depends on the story.

The round time frame example

The Marines outside the building hear the flashbang go off. One turns around and aims his rifle inside as two Spetsnaz enter bent on killing his two buddies. The few meters to the window are easily covered in the same time the Russians enter the room. He takes aim and fires, but the following events are so split second demanding I need a more precise time frame. Time once again slows down and game moves to beats.


Beats and Tics

A beat is a small unit of time equal to about a second, give or take a few fractions, in which an individual action may be taken. It is intentionally left ambiguous to prevent disputes. You know with the guy who actually does the rate of fire calculation from 5400 rounds per minute to the second, or the one who, when hacking a device, actually does the bandwidth kilobytes per second and disputes it should or shouldn't have been possible. Remember fun always supersedes mathematical precision.

A beat is in turn made up of four tics. Tics is in turn a point difference in reflex rolls (something like an initiative roll). A reflex roll is done against the character's reflex value. Tics can have negative values if the player rolls below the reflex value or positive if the player rolls above. Actions are then ordered from most negative tic values (greatest lead) to most positive values (slowest response). After that every four tics grants another action (beat) to the character as the following example shows.

Beats and tics example

The Spetsnaz and Marine roll reflex. The Marine rolls a very good -8 point difference below his reflex score, the Spetsnaz roll -4 and -2. Ordering :

-8 : Marine
-4 : Spetsnaz 1
-2 : Spetsnaz 2

The Marine takes his action at tic -8. He unknowingly shoots the faster Spetsnaz 1 and kills him. Four tics go by and the counter goes from -8 to -4, it's the Spetsnaz turn, but he's dead, bad luck. It is also the Marine's turn as he gets a beat every four tics, one a -8, one at -4, one at +0 and so forth. He attacks the last standing Spetsnaz 2 and kills him too. The Marine would get another attack four ticks later, but there's no one left to kill.

Had he failed to kill Spetsnaz 2, the Spetsnaz would have taken his action at -2, the Marine would have been able to act at +0. If the Spetsnaz was not neutralized by then another attack would be granted at +2 and so forth as show in the following table.

This table shows how actions would take place if none of the members involved were killed or disengaged. A tick is about one quarter of a second.

Tic Count Marine Spetsnaz 1 Spetsnaz 2
-8 Action


-7



-6



-5



-4 Action Action

-3



-2

Action
-1



0 Action Action

1



2

Action
3



4 Action Action

5



6

Action
7



8 Action Action

9



10

Action
11




Friday, October 11, 2013

The big five character traits

So far attributes have been the key values that define a character and that convert directly to game mechanics. They help in actions such as skill usage, problem solving and combat, but in no way describe the way the character behaves, his morals, the way he or she responds under different situations. Now I'm adding a few more traits to make things more interesting. To flesh out the character with desires and fears, virtues and vices, and moral strengths and weaknesses.

The first are the big five character traits: openness, conscientiousness, extraversion, agreeableness and neuroticism. These five values will help describe and record how the character tends to behave under different conditions. The player may choose the values between 1 and 10 or simply roll them and play what comes out.

These five basic traits will help define actions which will in turn mold the character throughout the adventure. Aside the big five character traits live saints and daemons, the angels and ghosts of personal experience. Saints and daemons live in the character's mind and both will help him or her overcome the hardships encountered. The former with a benefit and the later at a cost. With time these will grow and change the character's perception of the world around the character, of life, of others and him or herself.


"Now you might not believe it, but under fire Animal Mother is one of the... finest human beings in the world. All he needs is somebody to throw hand grenades at him the rest of his life." (Pvt. Eightball, Full Metal Jacket)

The Big Five Character Traits

Character traits are being added as character description values. These range from 1 to 10 and are covered the in the following explanation.


A summary of the factors of the Big Five and their constituent traits:
  • Openness to experience: (inventive/curious vs. consistent/cautious). Appreciation for art, emotion, adventure, unusual ideas, curiosity, and variety of experience. Openness reflects the degree of intellectual curiosity, creativity and a preference for novelty and variety a person has. It is also described as the extent to which a person is imaginative or independent, and depicts a personal preference for a variety of activities over a strict routine. Some disagreement remains about how to interpret the openness factor, which is sometimes called "intellect" rather than openness to experience.
  • Conscientiousness: (efficient/organized vs. easy-going/careless). A tendency to show self-discipline, act dutifully, and aim for achievement; planned rather than spontaneous behavior; organized, and dependable.
  • Extraversion: (outgoing/energetic vs. solitary/reserved). Energy, positive emotions, surgency, assertiveness, sociability and the tendency to seek stimulation in the company of others, and talkativeness.
  • Agreeableness: (friendly/compassionate vs. cold/unkind). A tendency to be compassionate and cooperative rather than suspicious and antagonistic towards others. It is also a measure of ones' trusting and helpful nature, and whether a person is generally well tempered or not.
  • Neuroticism: (sensitive/nervous vs. secure/confident). The tendency to experience unpleasant emotions easily, such as angeranxiety, depression, or vulnerability. Neuroticism also refers to the degree of emotional stability and impulse control and is sometimes referred to by its low pole, "emotional stability".

This diagram shows clear examples of a high or low score on each.


If you want to roll for these values instead of picking them a roll of 3d4 - 2 is done for each. This might result in a set of unexpected yet very interesting character traits to play.

If you want to see what your trait score is take a look a this test:
http://drphil.com/shows/bigfivepersonalityquiz

Saints & Daemons

"You have to have men who are moral... and at the same time who are able to utilize their primordial instincts to kill without feeling... without passion... without judgment... without judgment! Because it's judgment that defeats us." (Kurtz, Apocalypse Now)

Saints and daemons are background experiences that forged the character. A saint is a special gift that the character has that makes him or her excel at what she does. That special intuition, that charisma, that six sense, that particular endurance, motivation or spirit, maybe something his grandfather taught him or some self taught skill from living in the streets. Usage of a saint power grants bonuses to the character when doing certain tasks, success enhances the character's spirit, but failure in its usage may feed the daemons within.

For example, hard work and perseverance during youth may grant the character a special saint power to control his body very well. Enduring the hardships of hiding and concealment, able to stay perfectly still and control himself for long periods of time. This grants bonuses to rolls and actions related to scouting and concealment.

Daemons are also gifts that give power to the character, but do so at a cost. Using a daemon power will corrupt the character and make the daemon even stronger. Working around a problem without using a daemon power will raise the spirit of the character. Much in the same way a saint grants bonuses, so does a daemon grant bonuses, but its usage, failure or not, slowly corrupts the character.

For example, an animal like instinct in the character grants her a bonus in reflex rolls. She will draw faster, react faster and foreshadow enemy actions. Using this power to gain an advantage in a shoot out would result in a more effective, yet more vicious attack and the slow corruption of the character's soul.

Drive


When I go home people'll ask me, "Hey Hoot, why do you do it man? What, you some kinda war junkie?" (Hoot, Black Hawk Down)

The drive is a thought, ideal or wish the character has that fuels his or her life. It can be a mid or long term goal, it's what pushes the character on through the darkest moments. Drives change and evolve, but above all drives are challenged. The character's traits will dictate how and how well the drive's goals are pursued.

Will the drive be banal and superficial and unable to push the character forward in dire moments? Will the drive be too overwhelming and push the character to a breaking point or leave him to be consumed by his or her daemons as the character does everything in his or her power to achieve the goal? 

The drive also represents the character's interests and in a way, ego. Strong changes in drive may result in a high impact on the character's personality. Drives that lead to disappointment can result in the birth of new daemons in the character or heavily accentuate basic traits. Usually not in the stronger more virtuous manner.

Oh, maaaaaan and I was getting short. Four more weeks and out, now I'm going to die on this rock. This ain't fair man. (Hudson, Aliens)


Image source
http://www.datingphilosophy.com/2013/01/28/the-big-five/

Tuesday, October 08, 2013

The devil within, saints and daemons in a character's personality

We all have daemons, even the lawful good paladin does. What keeps these daemons at bay is a good question, what keeps them at bay when one wields unchallenged power is an even better question.

Now that I've set the weapons in their sweet spot and mayhem is ensured I turn to the characters and their fears. They all have a virtue of some sort, a gift that makes them good at what they are. They also have a drive, something that makes them place themselves in harm's way, and behind all of this they have daemons.

What keeps these daemons at bay? What happens when everything begins to fall apart around the character? How and with what strength to they appear? What does the character do when under their influence? Above all, do they recede and when? What havoc do they leave behind? How many other character's daemons do they awaken in their paths?

Players will choose a saint, something that makes their character shine. This will be premonition, dexterity, perception, insight, whatever makes them good as their character. They'll choose a drive, something that pushes them to be all they can be. Finally they'll choose two daemons which they will try to keep asleep, but who will undoubtedly be nourished by the character's actions in the game.

Thursday, October 03, 2013

d6 Poisson encounters

The Imperial March trumpets in the background as you party moves silently through the star destroyer. You dive into cover as a group of storm troopers turns the corner and comes your way. It's the second group you've encountered in the last hour. They must be looking for something, are they aware of your presence in the ship?

The Poisson distribution named after the french Siméon Denis Poisson allows us to calculate the odds of events occurring within a set period of time, area or volume. For example on the average a group of storm troopers is encountered every half hour, how many will the party encounter in the next half hour? According to the following graph, following the orange dots we have 37% chance of having 0 encounters, 37% chance of having 1, 18% of having 2, 6% of having 1 and so on.


The cumulative distribution is as follows:

The numbers are as follows


Prob. Mass Cumulative
# events lambda = 1 lambda = 1
0 36.79% 36.79%
1 36.79% 73.58%
2 18.39% 91.97%
3 6.13% 98.10%
4 1.53% 99.63%
5 0.31% 99.94%
6 0.05% 99.99%
7 0.01% 100.00%
8 0.00% 100.00%
9 0.00% 100.00%
10 0.00% 100.00%

What's really cool, and those d6 fans out there will love it, is that the 5d6 - 5d6 probability curve looks just like the Poisson distribution for lamda = 1. So you don't need to remember those odds.



Roll 5d6 subtract another 5d6, divide by 3, round, and subtract one.

2 + 2 + 2 + 4 + 6 = 16
3 + 5 + 4 + 5 + 5 = 22

Difference = 6
Divide by 3 = 2
Subtract 1 = 1 encounter in the following half hour.

2 + 2 + 3 +1 + 6 = 14
6 + 4 + 4 + 4+ 1 = 19

Difference =  5
Divide by 3 = 1 2/3, rounded = 2
Subtract 1 = 1 encounter in the following half hour.

5 + 5 + 6 + 3 + 1 = 20
1 + 2 + 2 + 3 + 4 = 12

Difference = 8
Divide by 3 = 2 2/3, rounded = 3
Subtract 1 = 2 encounters in the following half hour



Wednesday, October 02, 2013

Spotting the Enemy

Spotting the enemy is of vital importance to being able to target and neutralize him. To spot someone there has to be a line of sight between the observer and the target. This means the observer will need to be exposed during the period of observation, making him a target of enemy observers and quite possibly enemy fire.

I touched a little bit on this issue in my Surfing Bird post. Was no one looking down that street when the first VC ran through? Did they look, but only too late to raise their rifles and shoot?

Spotting falls beyond the simple die roll that dictates success or failure. Sure, your character spots the enemy, but when? In time to react or not? The sniper sees the enemy dash through the street. Does he catch him in time to aim and shoot? Or did his sweep of the area come too late and allowed the runner to make it to the other side before the round goes off? When will the patrol that does routine walks through the area come around again?

These can be answered by giving odds of occurring every so many seconds or minutes and then roll until the patrol comes around or the sniper spots its target. The issue with this is that the odds are not always the same minute after minute or second after second. If a patrol comes around every 60 minutes it would be very improbable that it comes back ten minutes after it passed. So rolling every ten minutes with a 15% chance of occurrence is wrong. Same thing occurs for a spotter. He can't have eyes everywhere so at some point a character is safe to raise his head to look for enemy positions. The odds of the spotter looking back into the area is slim. But the question is for how long?

Lets look back at the runner example. It takes him 7 seconds to run across a street. A sniper is scoping the area. At what point in the run does the sniper spot the runner? In the beginning, in the end or halfway through. And how does this affect the response time of the sniper. He still needs to estimate range and lead the runner. If the runner is spotted at second 5 it may be too late to get a clear shot. If the runner is spotted at second 1 he's most surely dead.

Instead of looking at an initiative roll will a flat probability curve and have it determine when an event happens or have a long succession of d100 rolls to see if it happens at a given hour, minute or second, I'm looking for a single roll that says : "the patrol will return in 22 minutes" Such probability curves exist, one such example is the Poission Distribution  (pronounced [pwasɔ̃]). It helps answer questions like given a rate of occurrence of an event, what are the odds of one, two, three, four, etc. events occurring in the same period of time.

So instead of rolling every minute to see if the patrol returns I can determine how many times the patrol will come around in one hour by simply using the Poission distribution. On the next post I'll dive into how to do this without having to solve this:



Sunday, September 29, 2013

Full Metal Cthulhu

A team of eight of the best men and women an army can provide. The best cold weather equipment that technology and money can buy. A simple objective: a recon operation in Antarctica. Go in, gather information, get out. What could possibly go wrong?

This is a summary of yesterday's game, enjoy.

----

Few things scare players more than an mysterious and larger threat  than the already huge threat they think they are facing. When they entered Antarctica for an undercover recon operation of a strange thermal activity, things were bad enough already. They were cut off from any help as military operations are strictly prohibited in the continent. Add to that the unrelenting cold weather of Antarctica, the near imminent winter and the six month night it brings, the fact that they're operating in practically continual daylight and the area of operations is centered on a major glacier with the risk of sudden gale katabatic winds from the super cooled Antarctic plateau.

As if things weren't bad enough when they reach the target point they realize there is indeed a bunker complex, that it is not a natural phenomenon and that the masters of cold weather warfare, the Russian Spetsnaz are there. Entering the complex and seeing what is inside was clearly not going to be easy, but things got ten times worse when the Spetsnaz themselves started disappearing. Who, or what, is doing away with the masters of the game in their own turf?

OP GENTOO

Strange heat signatures have been detected at the top most area of the Beardmore Glacier. A team has been requested to investigate the area by setting up "scientific outpost" at the base of the glacier and go on foot or snowmobile to the area to gather information. Determine if the activity is of natural origin such as geothermal activity or something man made.

The following satellite image shows the location of the heat signatures.


The mission begins at McMurdo Station. The team of eight arrive on February 4, planning to set off to the Amundsen-Scott station on February 8 and be dropped off half way there as part of a ice and ozone research team. The leader Major Darya Groshkov is in charge of the "research team" she is also the unit's intelligence specialist and fluent in five languages aside from English: Russian, Spanish, German, Swedish and Norwegian. Carl Owens is the team's medic. Two heavy weapon specialists accompany the unit: Anthony Mc Knight and Andrew Hayes. Two snipers also integrate the group Thomas "The Eye" Young and Mike "Whisper" Gonzalez, the highest ranking NCO in the team. Two more members complete the team Justin "Hawk" Reed and Martin "Hard Head" Wood, both Airborne.

The plan is simple. Setup a decoy scientific station halfway to the south pole, at the mouth of the Beardmore glacier, this will be OP Gentoo. From there go up the glacier's steep incline to the place the heat signatures have been seen, survey the area and get as close as possible to it. If foreign nationals are found try to make contact and obtain as much information as possible. That's what Darya is there for.
Problem is "halfway there" is a 10 day trip which gets delayed four more due to bad weather. By the time the set up camp it's already February 22 and night is less than a month away. Will they make it?

Once setup at the base of the glacier things got interesting. First the team must make it up the glacier for the first 120 km. This under all daylight conditions, freezing temperatures, strong winds coming down the glacier and the ever present risk of crevasses that can swallow the whole party.



After a day's travel they setup RP Echo and start operating from there. An ascent up the mountain sets them in an ideal spotting position they then call OP Alpha. All operations and observations then take place from there for next few days. From OP Alpha the survey the two bunker positions at the entrance of the now clearly human inhabited complex. These are called X-Ray and Whiskey. The main complex being called Yankee and a strange tube/pipeline with a steaming lake is called Zulu.
All seems to be going well as the party monitors the activities of the now clearly identified Russian Spetsnaz in the area. Suddenly on the first of March X-Ray is found empty. The Russians in Whiskey are more interested in monitoring what is going on at X-Ray than doing their normal watch duty of guarding the glacier's entrance. This makes the party scramble a plan to infiltrate the complex through the X-Ray bunker and find out what happened there. Making use of the now scant hours of twilight they're getting they go around and approach X-Ray from the north, keeping themselves hidden from Whiskey.

They enter X-Ray only to find and abandoned complex. Two bunker areas are found deserted with the clothes and personal items of those who stood guard there. A personal diary which Dayra translates to English reads, "The sounds at night, if you can call it that in this place of permanent daylight, have become more frequent lately. They are followed by that strange penetrating smell. More and more we are convinced we are not the only ones in this place. Who built this and are they still here? If not them then who or what lives here? Antarctica is thought to be a desert this far south, but we fear we are not alone here." That is the last entry in the diary and it is dated just a day before, prior to the strange disappearance of the guards at X-Ray.

The arrival of a patrol to X-Ray only increases the tension in the team. Why would the Russians send a team to patrol their own outpost. What are they searching for and why? Do the know what happened to their comrades? Unfortunately that answer will remain unknown as they were neutralized by Hayes and The Eye when they were unfortunate the spot the team inside X-Ray.

The big room in X-Ray is a complex dome/storage area. A complex set of pipes and valves criscross the area and stairways lead to other middle levels and decks. Two corridors lead out aside from the one leading in from the outside observation post. One to what appears to be another set of living quarters and the other to a simple dead end. On both service shafts are found leading to an underground rail tunnel that seems to lead all the way to Yankee.


The party now stands ready to walk down the tunnel. Marks on the floor show footsteps leading in and out as well as indications of something, possibly bodies or prisoners being dragged away from this area.

Join the next session and find out where this leads to and who or what is behind these strange disappearances.


Remember, it's already March 3. It's a two day trip back to RP Echo on foot, or a few hours on snowmobile, if they work. From RP Echo to OP Gentoo it's 123 Km. A day's trip on snowmobile if the weather permits, but 8 or 10 days on foot. From there it's still three of four days back to McMurdo. Sun sets on March 20 for a good 6 months of winter night. Do the math and see how tough things are getting. See you next weekend, and good luck.



Image sources
Google Maps
http://peakbagger.tripod.com/Climbs/Clemenceau/clemenceau.htm
http://airsoft.ua/content.php?r=73-GEN-III-ECWCS-5-%D1%81%D0%BB%D0%BE%D0%B9


Tuesday, September 24, 2013

Redefining range


As I moved from bow and arrow to long range rifles I carried over a mistake. The naked eye can't see well at the still effective ranges modern machine guns and rifles have. The classic increasing "to hit" penalty by range is not a good model anymore.

If I do a gradual drop in precision over range when using an iron sight the weapon becomes too deadly because I'm not taking into consideration the much faster drop introduced by the shooter's eye. There's a gradual loss in precision due to the weapon's craftsmanship and ammunition properties, but there is a much larger drop in precision due to the naked eye's ability to distinguish a target.

This calls for a separation of modifiers. One for the weapon's range performance (which may vary with ammunition type too), and another for the visual capacity of the shooter (which may be enhanced through optics).

I could factor in the optics into a single modifier to the weapon, but that brings two problems. I'd have to write weapon stats for each type of optic device: reflex, holographic, and scopes by amplification (3x, 4x, ... Nx). This also makes Joe "Carnival" Sniper quite good at shooting with a sniper rifle. He just picks up one with a 9x scope and fires away. But it takes more skill than that to use a sniper rifle at those ranges and I want the game to represent it. I'm even thinking about making the sniper character require a well trained player. It takes a bit more to play a sniper and I feel will be a gratifying feeling for the players masters the sniper as a character class. More on this to come in my next post, Designing the Sniper.

Now back to weapons and the crunchy part of this idea.

Usually weapons have a range modifier based on distance, but no sight modifier. That is, a modifier that adjusts for the attacker's ability to pinpoint the target. A weapon may have a huge range and standard modifiers would add values for different ranges up to the maximum effective range of the weapon. For example 0 at short range, - 1 at medium range, - 3 at long range, etc. This works well with bows, their range limit is within visual range of the naked eye. Firearms on the other hand have ranges that exceed the naked eye's capacity to distinguish things and thus aim correctly. So a weapon, if equipped with basic iron sights, will become ineffective at hitting a bull's eye a lot sooner than it stops being lethal or precise. In other words at 400 m the bullet is still flying pretty much where the sight said it would, but the eye can't pin point the target as well anymore and be precise in the alignment between target and sight. Image amplification is needed.

An error I believe I'm borrowing from other games is taking the range penalty to include both weapon precision and shooter sight. Sight, I believe, should be a penalty applicable based on the character skill and the optics being used, not the weapon's quality. It applies to a human's eye and in the case of fantasy settings it could be modified by race too.

Currently I'm using one modifier for range, the weapon's. But this makes modeling difficult because iron sight weapons seem to be too deadly at ranges where the target could hardly be seen with the naked eye. Optics add benefits to the weapon's effectiveness when in truth they should add better "aim" to the shooter. There are two values so to speak: the weapon's ability to shoot straight and the shooters ability to make use of this precision.

Normally the weapon's quality and ammunition drift in flight lead to the range modifiers. For example: point blank, short, medium, long and extended range all add increasingly negative modifiers due to bullet drop, wind, bullet spin and barrel craftsmanship. Usually with bows dexterity and fighter skill add in the bonuses to compensate for range. In the case of modern weapons optics also add in a modifier by adding image amplification and improving aim.

The option of separating them into to values may be questionable, specially since it adds another value to consider when resolving combat. Yet I believe it simplifies the weapon and sight models considerably and makes skill even more relevant and also easier to implement.

Here's a comparison between both models:

Classic range model

A weapon, say an AK-47 has different ranges: point blank (20 m), short (80 m), medium (200 m) and long (400 m). These are examples and not meant to be based on the real weapon. The modifiers are as follows: 0, -2, -5, and -7. A scope adds a +3 modifier, or for a more detailed model: + 4, + 3, + 2 and + 2 according to each range bracket.

This a simple and quite common and easily understood model, but it has its flaws. What if the weapon is precision manufactured? Will the penalties be less? Why? At long range the error introduced by the naked eye is more than any benefit in better craftsmanship. At 300 or 400 meters the target is so small it is hard to make a precise aim with just an iron sight.

Now the scope gives a flat + 3, or in the more detailed model a succession of values depending on range. Will this be so for weapons that have an effective range of 400 m as those that have an effective range of 800 m? Why? Scopes bring things closer, but something 800 m is still twice as far as 400 m and shouldn't get the same benefit.

Even with the improved model with a modifier for each range, what happens when the same scope is fitted on another weapon that has different ranges? For example point blank (30 m), short (120 m), medium (300 m) and long (600 m). Does it improve it just the same? Why does this weapon get a + 3 at ranges up to 120 m when the AK got + 3 only up to 80 m? What happens the other way around when the weapon's range decreases?

What about skill? Putting a scope on a sniper rifle does not a partisan a marksman make. Really long range rifles are usually trimmed for a distance and quick adjustments outside its set range setting are slow to do and require skill and preparation. That is why the scope have mil marks that help to compensate quickly, but even then there is a limit. Modeling this with a classic range and scope model is difficult. The scope is effective up to 2000 meters, but at any one given moment the sweet spot is plus/minus 100 or 200 m.

Range and sight model

Now let's look at it as two separate and overlapping modifiers. One is sight and the other is weapon precision. Weapon precision is how good a weapon performs at a given range. It is similar to the classic model of range modifiers. Let us assume for the moment that there are three ranges: short, medium and long. These ranges have modifiers depending on weapon quality and they drop of gradually or harshly depending on weapon type. For example : 0 , -1 and -3 for a rifle. The ranges for the rifle are short 50 m,  medium 150 m, long 300 m.

Weapon Modifiers
50 m : 0
150 m : -1
300 m : -3

Sight modifiers on the other hand are fixed by the human eye. For example 0, -3, -6, -12 for ranges of 50 m, 100 m, 150 m and 200 m. When using the weapon the modifiers add up.

Sight Modifiers
50 m : 0
100 m : -3
150 m : -6
200 m : -12

At 40 m the modifier is 0, 0 from rifle range and 0 from sight. At 120 m the modifier is -7, -1 from rifle range and -6 from the sight modifier. At 180 m the modifier is -15, -3 for rifle range and -12 for eye sight. As you can see the weapon quickly becomes ineffective at such ranges, but the weapon model is still simple and not affected by optics.

Now let's put a 3x ACOG scope on the rifle. The magnification means everything seems closer to the shooter's eye, but only to the eye not the weapon. The bullet still has to travel the full length of the distance to target and weapon craftsmanship and ammo selection plays a huge role here. The target at 40 m is now apparently 13 m away, the target at 120 m is now apparently 40 m away and the target at 180 m is now apparently 60 m away. This improves the sight modifier greatly as these are taken at the apparent distance not actual distance. The weapon's modifiers are still taken at the real distance to target. Taking the same modifiers as the previous example:

Weapon Modifiers
50 m : 0
150 m : -1
300 m : -3

Sight Modifiers
50 m : 0
100 m : -3
150 m : -6
200 m : -12

The examples convert to:

40 m : 0 modifier before, now apparently at 13 m, 0 modifier now : 0 for weapon range modifier (use real distance of 40 m) and 0 for sight modifier (use apparent distance to target of 13 m)

120 m : -7 modifier before, now apparently at 40 m, - 1 modifier now : -1 for weapon range modifier (use real distance of 120 m) and 0 for sight modifier (use apparent distance to target of 40 m)

180 m : -15 modifier before, now apparently at 60 m, - 6 modifier now : -3 for weapon range modifier (use real distance of 180 m) and -3 for sight modifier (use apparent distance to target of 60 m)

Notice how effective adding 3x amplification was to the weapon's performance. The shot at 120 m got a seven fold improvement and the shot at 180 m nearly a three fold improvement.

This mechanism adds complexity because it requires another value to add when calculating modifiers, but it simplifies weapon modeling as a whole. As you can see the rifle is still the same and the player doesn't have to deal with lots and lots of weapon stats, each for a different attached scope. The weapon is one thing and the scope is another and they're now easily combined.

Next post will cover the sniper and his rifle in more detail.


Image source
http://www.archivio.aria.compressa.org/gallery/lst_image.php?pid=760&size=fullsize

Monday, September 23, 2013

Lead aim initiative modifiers for bows

The farther out your target is the more an initiative penalty your character gets. In another post I talked about tabletop RPG frames per second (FPS) and how long things take to propagate through the battlefield. Indicating that some effects, like arrow attacks, are not immediate. I came up with some modifiers for initiative based on range. Now I'll talk about another important element required for long range shooting: lead. Leading is the act of putting the arrow or bullet ahead of the target so the shot goes to where the target will be and not where it is now.

Now, you can't lead a target if you don't know the target speed, and you can't know the target speed if you don't measure it. To measure it you must wait, wait for the target to move enough to make an accurate guess. How does range affect initiative? Simply put, the further away the target is the harder it is to calculate the lead. The target will have to move more for your character to guess better and a bad guess will be more significant at that long range.

For example at Pathfinder lists the heavy repeating crossbow as having 120ft range, that's 40 yards. An 8 inch target at 40 yards measures 5 mils. At 80 yards the same target measures about 3 mils, 2 mils at about 120 yards and 1 mil at the weapon's max range of 200 yards. But 1 mil is so small you might not even see the target, much less notice it moving until it takes a step or two.

A simple rule is to add 1 point penalty for every range increment in range. If the weapon has a 80ft range anything up to 80ft has a 1 penalty to initiative if the shooter wants to lead the target, above 80ft and up to 160ft the penalty is 2, and so forth up to 5.

The shooter can fire without leading, but if the target moves in the round the shot enjoys a 1 point penalty for every range increment. For example, a bow with 80ft range fired at 140ft (less than 160ft which is 2x base range) suffers a 1 point penalty to initiative if the bowman leads the target or a 1 point penalty to hit if the bowman fires quickly and the target moves. These to hit penalties are added to the already calculated penalties for range.

Image Source
http://allyoucangame.wordpress.com/

Friday, September 20, 2013

A day in Antarctica

Next weekend my players will spend a day in Antarctica. They will land at McMurdo station, prep their gear, fly to Amundsen–Scott station (geographic south pole) and from there they will be "smuggled" as a science crew to get close enough to their target. A strange complex in the mountains and their inhabitants, a group of rogue mercenaries up to something. After the drop off it's all on foot and snow mobiles to the merc complex. Sneak, spy and even infiltrate are their orders.

Quite a lot for a day's work you'd think. Well think again because a day in Antarctica lasts a whole six months. That's right. Although the duration may vary the further north you go, at true south sun is coming up tomorrow September 21 at 5:26 am and ain't setting for a whole six months. That gives our brave adventurers quite some time to finish their mission. But let's not let them get too confident because when the sun sets night will last a whole six months too, and not even the Energizer bunny is going to keep their NVGs going that long!


Sunrise marks the beginning of spring, the arrival of warmer days and supply airplanes. Warmer is a relative term there, it means going from an average high of -55°C (-68°F) in winter to -26°C (-14°F) in summer. It also literally means the appearance of the sun over the horizon. something that has been missing for the last six months.

No wonder "Here comes the sun" by the Beatles has been played at least once to welcome the sunrise and nowhere is the song's lyrics more fitting after six months of no sun.

Probably unaware to many is the Sun's role in bone structure and mood swings of human beings. Vitamin D is produced in the skin. Without it the body suffers. It is strongly related with bone issues like osteoporosis, rickets (bone softening) in children and osteomalacia. "Vitamin D deficiency has been associated with increased risks of deadly cancers, cardiovascular disease, multiple sclerosis, rheumatoid arthritis, and type 1 diabetes mellitus." (http://ajcn.nutrition.org/content/80/6/1678S.full)

Lack of sunlight is also related to depression as serotonin is dependent on sunlight as well. Without it mood swings and even suicidal tendencies could emerge. Men respond differently to serotonin deficiency than women "...men became impulsive but not necessarily depressed. Women, on the other hand, experienced a marked drop in mood and became more cautious, an emotional response commonly associated with depression." (http://www.webmd.com/depression/features/serotonin?page=2)

So let's start piecing things together. Antarctica is a wonderful place where firearms tend to malfunction, get stuck, become brittle, can't be fired as quickly in a stressful situation, food and water freezes, your next step on the snow could be your last, you might find yourself stranded in a pancake of snow as flat as the eye can see and on top of that the lack of sunlight creates painful bone diseases and lack of brain chemicals that lead to mood swings. Isn't this a lovely setting??

Of course not all Antarctica is all day for six months and then all night for another six months. The amount of light is shown on the following diagram. As you can see light gradually diminishes and then increases over a period of months, not hours.




At McMurdo station the light fluctuation is as follows:


Even though there is more fluctuation in sunlight during the day it never really becomes daylight during winter, specially the coldest months of June and July. It also never quite gets dark during summer. Posing another threat to the party: visual contact.

Moving undetected at night is kinda hard if night doesn't come, and waiting for night fall is quite a long wait. Are you getting stressed already? Wait until your character's serotonin levels begin to drop. Mood swings with heavily armed men and women. What a great mix!!!

Operating in days that have day and night periods during the day pose a serious threat of exposure and extreme cold as those days occur in the coldest most bitter months of the year.

Daylight operations are the only viable alternative as they fall within the warmest months of the year and enjoy more transportation in and out of the area. Although there is a road, the McMurdo South Pole Highway, airplanes are the preferred means of transportation in and out.

Daylight months also provide a good cover story for the team's presence in the area. As a cover up science team their movement will become less suspicious. In the summer the south pole Amundsen-Scott Station population peaks at 200, making their presence and activities less notorious to watching eyes.

We'll see how they fare. The have a few months to finish their task. Their last chance of a ride home is the last C-130 leaving for McMurdo just before sunset in March. If they miss it they'll have to join the winter-over and enjoy the movies. I hear the first played just after sunset is The Thing followed by The Shining. No kidding, that's what they do over there. Of course a whole six months of darkness presents so many great opportunities for adventure so who would want to miss that?




Amundsen-Scott Station Temperature Table

The following table shows the average and record temperatures per month as well as the amount of sunlight at the south pole station.

Climate data for the South Pole
MonthJanFebMarAprMayJunJulAugSepOctNovDecYear
Record high °C (°F)−14
(7)
−20
(−4)
−26
(−15)
−27
(−17)
−30
(−22)
−28.8
(−19.8)
−33
(−27)
−32
(−26)
−29
(−20)
−29
(−20)
−18
(0)
−12.3
(9.9)
−12.3
(9.9)
Average high °C (°F)−25.9
(−14.6)
−38.1
(−36.6)
−50.3
(−58.5)
−54.2
(−65.6)
−53.9
(−65)
−54.4
(−65.9)
−55.9
(−68.6)
−55.6
(−68.1)
−55.1
(−67.2)
−48.4
(−55.1)
−36.9
(−34.4)
−26.5
(−15.7)
−46.3
(−51.3)
Average low °C (°F)−29.4
(−20.9)
−42.7
(−44.9)
−57.0
(−70.6)
−61.2
(−78.2)
−61.7
(−79.1)
−61.2
(−78.2)
−62.8
(−81)
−62.5
(−80.5)
−62.4
(−80.3)
−53.8
(−64.8)
−40.4
(−40.7)
−29.3
(−20.7)
−52.0
(−61.6)
Record low °C (°F)−41
(−42)
−57
(−71)
−71
(−96)
−75
(−103)
−78
(−108)
−82.8
(−117)
−80
(−112)
−77
(−107)
−79
(−110)
−71
(−96)
−55
(−67)
−38
(−36)
−82.8
(−117)
Mean monthly sunshine hours55848021700000604346005892,938
Source #1: Weatherbase [11]
Source #2: Cool Antarctica [12]





Image sources
http://www.nhm.ac.uk/nature-online/earth/antarctica/antarctic-conservation/blog-archive/?m=200904&paged=2
http://www.telegraph.co.uk/news/worldnews/southamerica/falklandislands/9158097/The-secret-Falklands-suicide-mission.html
http://commons.wikimedia.org/wiki/File:LC-130R_Hercules_of_VXE-6_taking_off_from_McMurdo_Station_1987.JPEG

Sources
http://en.wikipedia.org/wiki/Amundsen%E2%80%93Scott_South_Pole_Station
http://en.wikipedia.org/wiki/McMurdo_Station
http://www.antarctica.gov.au/about-antarctica/environment/weather/sunlight-hours
http://ajcn.nutrition.org/content/80/6/1678S.full
http://www.webmd.com/mental-health/news/20021205/unraveling-suns-role-in-depression
http://www.serotune.com/blogs/articles/2659862-what-are-the-symptoms-and-causes-of-serotonin-deficiency
http://www.psychologytoday.com/blog/evolutionary-psychiatry/201105/sunlight-sugar-and-serotonin

Wednesday, September 18, 2013

Firearms in cold weather

The next adventure takes the players to the coldest place on Earth, Antarctica. The setting will push the limits of the characters and their equipment. Fortunately they will be equipped with the best of the best. They'll carry Accuracy International's Arctic Warfare rifle and the world's best cold weather clothing.






The Artic Warfare rifle is specially designed to endure extreme cold temperatures. It has a deicing feature that allows it to be operated as low as -40°C (-40°F). Which is really good news! Bad news is the mean temperature in Antarctica is -57°C (-70°F). Did I mention Antarctica has the record for the lowest temperature recorded over land? A chilling -89.2°C (-128.6°C)!!!! At that temperature your car's exhaust snows CO2 flakes. That's right! No fear of suffocating with your car exhaust, no sir, it's going to be snowing dry ice!!! I know there's a joke to be made there somewhere, but I digress.

Extreme cold is definitely bad for weapons, but sooner or later the party is going to enter some warm place, like a shelter or building and that's going to make things so much worse!!! An extremely cold weapon will quickly condense water on its surface. That means it will build up dew drops inside it which will freeze up again the weapon exits the building. Isn't this just wonderful? A five minute chase in and out a building is enough to render all your firearms useless. I can't buahahahahaha loud enough! Am I an evil GM or what?!?!

Here are a few things that make weapon use in extreme cold weather problematic (aside from issues with the ammo itself) :

  • Lubricants become very thick and may even freeze too. Weapons may have to be used without any lubrication so as to prevent stoppage. Fortunately our players are on a government sponsored trip and will have access to United Bio Lube's "Bio Arctic", which is rated at up to -50°F. Which is good for Antarctica's summer, but come winter and well... buahahahaaha....
  • Air humidity. As mentioned before bringing a cold gun into a warm room will immediately cover it with a thin film of water that will quickly freeze if the weapon is once again taken outside. This ice can block the internal components even when the weapon is completely dried on its outside. Aside form jamming, this can be damaging in gas or short throw piston weapons.
  • Rapid heating. Remember the T1000 scene? Or better yet the Aliens 3 scene? Hot then cold or cold then hot can be damaging to a weapon. Rapid increases in temperature can begin fracturing the barrel. Rounds should be put down range at a slow pace before the weapon is placed in a higher full auto o cyclic rate.
  • Accidentally firing the weapon. It's cold and the character has big gloves on that make it hard to feel just how much pressure is being placed on the trigger. Even with a modified trigger and more room for a gloved finger firing the weapon with precision can be a challenge. Option b is exposing the finger during the shot, but that endangers it to frostbite, and numbness can be as bad if not worse than the glove itself.
  • Air density. Last, but not least, air gets denser as temperature drops. About 1% for every 4.5°F (about 2.5°C). This will affect the range and effectiveness of the weapon.
If this wasn't enough did I mention they're going against the masters of cold weather warfare? The Russians and their AK-47, good luck!





Sources

http://www.chuckhawks.com/firearms_cold_weather.htm
http://www.backwoodshome.com/articles2/ayoob79.html

Image Source

New Zealand Army - SAS cold weather training in mountain environment.
http://www.army.mil.nz/about-us/who-we-are/nzsas/sas-gallery/4.htm

An Afghan soldier in Kamdesh, a village in the Nuristan province of Afghanistan. Winter 2006,http://news.bbc.co.uk/2/hi/in_pictures/7333540.stm