Sunday, September 15, 2013

FPS, the economy of consequences

What's the frame per second rate of your tabletop RPG?

Games handle the economy of actions in many ways, but seldom is there a measure of the response of the environment to such actions. Nature, it would seem, is not a player in games. Looking at various games and means to keep tabs on actions and time I'm convinced there is some implicit FPS rate that nobody talks about, but varies from game to game. The choice of time frame directly affects the narrative power of a game as it dictates how PC created effects propagate and how nature provides feedback to character about the things occurring around them. Effects are not instantaneous and the disregard for this can cause issues in tabletop RPGs when the action speed is too high. Let's say it's not captured "on screen" because the frames per second are too low. Let me explain..

+Cory Owens does a great work summarizing the Economy of Actions in various games. In his blog he enumerates a variety of ways to keep track of character actions in a certain time frame and indicates the pros and cons of each. The balance generally tilting between detail and ease of use and speed in the game.

What I want to look into right now is how those different economies of action affect the narrative potential of the game and how they enable or not the potential a player has to manifest the power of his or her character into the story. Let us put the issues of complexity and overhead aside for a moment and ponder on the impact of more detailed time measurements.

Minuscule time measurements allow for heart stopping moments in the story. Recent playtests have shown the importance of half second or quarter second differences between PC and NPC actions. Their impact on the story is outstanding. Within the context of a modern warfare game, like the one I'm running, half a second or less is the difference between life or death. Modern RPGs not your cup of tea?, worry not, I'll be getting to arrows soon, there's even a video.

Getting back to the bullets. Will your character respond in time, set that shot of before the entering enemy can hit my character? Will the bullets fly across the field fast enough to reach the target before it shoots back or worse, detonates a bomb? Those details can no doubt be added by a purely storytelling process but, as is quite common sometimes, reality surpasses fantasy, and having a "realistic" rule system that lays the groundwork for such mechanics can open a whole set of truly fantastic possibilities in a game.

So let us look at frames per second as a concept. How the story unfolds not only in player actions, but also in the consequences of their actions. Even light, as fast as it is, takes time to travel from one point of the galaxy to another. In much the same way bullets, arrows, magic and all sorts of effects take time to propagate through. Could we call this the "Economy of Consequences"? The economy of consequences isn't about the casting time of a spell, as in I cast a spell and four seconds later it occurs. No, that's not what I'm talking about, it's about a frame by frame representation of the spell actually manifesting itself. The four seconds have already gone by, now the spell, the fireball, wall of fire, lightning bolt, whatever, is racing towards the enemy, what's happening then?

Turn based games allocate a certain amount of time to each player, the player takes an action and then the next player's turn comes up, he or she takes and action and so on. There's an action and a consequence of said action: a sliced goblin, charred orcs, shattered skeletons, etc. In such games actions take a time to occur, but consequences are immediate. There's an economy of actions, but no economy of consequences.

Now let's imagine we break a 10 second round into one quarter second time frames and loop through character actions at that rate. Once again, set aside complexity and bear with me. What happens then? Every player gets an action every 250ms. Not that we'll actually ask each player what their character is doing, we'll just update the setting ever 250ms instead of every 10 seconds or every action taken, which may take a few seconds or more. To analyze this let's look at a combat encounter example.

Our brave adventurers are corned by a group of orcs and are fighting back when a group that broke off returns and finds them in trouble. They roll for initiative, two archers from the returning party fire at the orcs killing two, the orc chieftain turns and fires at the archers, the pinned and cornered fighters slice up a couple of orcs, the orcs attack the fighters and the archers fire at the orcs again. End of round.

Now let's speed up the frame rate at 250ms per frame. Nothing happens for the first 3 frames, then the archers fire, not much happens for the next 8 frames, the orc chieftain turns, wait 3 frames, fires the bow at the archers, two frames go by, the fighters attack the orcs (there are more now, the arrows are not there yet and the will be dead orcs are not dead yet), a frame goes by and they slice up a few orcs, two frames go by and the arrows arrive hitting a few more orcs (did they hit orcs that were already killed by the fighters???), three frames go by the chieftain's arrow arrives and hits an archer, the archers fire a second volley, 15 frames go by, somehow nobody does anything, arrows arrive and hit the orcs.

Before jumping to complexity concerns let us look at the following video by Lars Andersen

He puts 11 arrows into the air before the first hits the ground just 8 seconds after it was shot. Don't think 250ms or 500ms precision is important? That's 8 seconds before you know if your target is hit or not. Do you shift aim to the next orc? There are 10 arrows in waiting, quick make up your mind.

Work on Weapons Free begun as a quest to create an RPG for fast action thriller games. This got me working on new ways to handle weapons and firearms, but the real trick seems to be in the measurement of time. Not only to allocate actions to players, but to track consequences. In the classic turn based systems your character can aim to fire when suddenly an RPG is fired your way (RPG as in grenade not a big fat rulebook). A roll for your attack is made and then a roll for the enemy RPG, damage dealt and turn ended. In a more action packed game, certain events must be able to intervene in the middle of someone's action. Let me replay the same round at a much higher FPS rate. Your character aims the rifle, an RPG is fired, someone yells "RPG!!!!", will your character mindlessly keep aiming and taking the shot because the rules dictate no action can be taken until the next round or will he or she instinctively seek cover?

In my subsuption post I talked about small, compact and loosely bound rules that worked in parallel and could be triggered by sudden changes in the scene which lead to some actions superseding others (namely saving one's life over taking a shot). To do so, the game needs to track the propagation of events, not only the occurrence of events themselves as instant effects in the game. The RPG is not fired and instantly hits the target, it takes a small amount of time, but that bit of time can mean the difference between being exposed or behind cover when it goes off.

It is my strong belief that common turn based systems create an effect in the tabletop RPG similar to network latency in an online video game, and I'll quote wikipedia regarding this:

" Additionally some games such as Quake 3 Arena perform physics, AI, networking, and other calculations in sync with the rendered frame rate - this can result in inconsistencies with movement and network prediction code if players are unable to maintain the designed maximum frame rate of 125 FPS. "

In the same way insufficient frames can cause glitches in a fast paced game such as Quake 3 Arena, so can insufficient frames cause glitches in tabletop RPGs dealing with the fast paced action of modern day action thrillers.

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