Saturday, July 25, 2009

Full Defense actions

This week I am discussing some of the issues behind the “full defense” actions in games. A classic full defense action is a type of combat maneuver in many games in which you spend an entire round (depending on how the game manages time) doing nothing but defend yourself, and in return the attacker suffers a penalty to hit you. In some games you have to declare the full defense maneuver without knowing whether you are attacked, while in other games you can declare full defense in response to being attacked. For purposes of discussion both have similar properties, although obviously the latter is a much more favorable rule.

The important game effect of a true full defense action is that it is not a maneuver performed for the purpose of winning the combat. In a straight one-on-one combat where your goal is to defeat the opponent without being defeated yourself, in the absense of extenuating circumstances, performing a full defense action is always a losing maneuver – it increases your chance of being defeated. Many games are deceptive in this regard, implying that a full defense action is an appropriate reaction to being attacked in a heated combat. When the full defense maneuver is named something like "Parry”, and you have the option to take full defense on some actions and attack on other actions, this may at first glance seem like a reasonable idea. But in fact, this is not so. Every round in which you perform a full defense action, you cannot hurt the opponent, but they have a chance of hurting you. In abstract terms, essentially what you are doing is taking a small amount of damage in return for slowing down the combat. But in a straight out one-on-one combat for victory, slowing down the combat (i.e. making it take longer to finish) has no benefit whatsoever, since the combat keeps going until one person wins or the other. So the full defense has no tactical value. It is only useful if there is some way in which the tactical situation is significantly different from this simplified straight up one-on-one combat.

As I mentioned, some games are deceptive and may even give combat example suggesting that it would be appropriate to occasionally respond to an attack with a full defense action, one with a deceptive name such as Parry or Block or Dodge. The trouble is that the kind of parry or block which one might perform as part of a duel is simply not at all modeled by the full defense action. In many games, that sort of defensive action is something the character is assumed to perform automatically as part of a normal attack action. So the good roleplayer should be describing how he blocked or dodged attacks which miss him, rather than actually using the full defense action. A classic full defense should be not be expected in this situation; a player shouldn’t be penalized with a lower chance of winning the battle just because he is creative in describing his actions. I really like how 4th edition D&D calls the maneuver “total defense”, making it perfectly clear that a full defense is an extreme action that takes you temporarily out of the fight.

However, full defense is only truly useless in the abstraction of the straight one-on-one combat, and only if the game does not define other interacting rules to make it more effective. So I will go over some of situations in which full defense can be effective – the situations that define what the purpose of a full defense rule actually is.

For the purposes of this discussion, I will define full defense as a “winning combat maneuver” in situations where it could possibly increase your chance of winning a straight up one-on-one fight, and a "losing combat maneuver" in situations in which it can do nothing but lose such a fight.

First, I shall describe some of the ways in which games can adjust the rules to transform a full defense action into a winning combat manevuer.

1. In some games, characters do not always have the same number of actions; some characters may earn actions at a faster rate than others. If a character is allowed to use full defense against every enemy attack action, and the character still has actions left over, he can use his extra actions to attack. This means that it is mathematically possible that this could be a winning strategy – that the reduction of the enemy’s chance of hitting could actually be more significant than the reduction to the faster character’s number of actions, such that the faster character gains a fighting edge by using full defense. In order for this to work, the defense bonus for the full defense action needs to be fairly large, unless for some reason the characters have far more actions than the opponents.
An example of this is Champions. In that game if you have a 6 speed and 11 dcv, and the opponent has 4 speed and 9 ocv, then if you dodge every time you are attacked, you lose 2/3 of your actions, but the opponent's chance of hitting is reduced by more than 3/4. Therefore, you come out ahead by dodging.
Unfortunately, Champions also shows the weakness of this approach. If dodging is good, then a lot of dodging is better. But if you dodge every enemy attack, then even your own offense is reduced by 2/3, and the fight would take 3 times as long to play out. Ignoring the question of who wins or loses, this just isn't fun because the fight becomes interminably long. And in fact, Champions characters actually heal at a fairly rapid rate during combat, so in fact the fight could go on practically forever. It is so impractical I’ve never seen anyone even consider trying this. It does mean that the fast character could choose to occasionally dodge just for fun without being penalized, which is amusing. But mechanically, the trade-off between effectiveness and tedium is not a very desirable one.

2. Some games give you a bonus in later rounds of combat when you perform the full defense action. In Torg, performing a full defense action successfully can sometimes let you draw an extra card. In the Lost Worlds combat booklet game (this is not an RPG, but still works as an example), if you perform a full defense action against the right kinds of attacks, the enemy may be pulled out of position and vulnerable to your counter attack. I like this method of turning full defense into a winning combat maneuver, it seems like a flexible and fun approach. It does not restrict whether the full defense bonus needs to be small or large, since you can simply adjust the additional bonus you are giving to be smaller or larger.
The tricky point here is that if full defense is a good way to set your next round of combat, you can easily end up in a situation where every character simply alternates between full defense and attack every other round of combat. This isn't a disaster, but it is strange and awkward. Both of the games I listed above have ways to prevent this problem. In Torg, you can only get a bonus card for dodging if defense is an approved action that round, and it is random which actions are approved each round. Lost Worlds is a game based on the “outguess” principle of rock-paper-scissors, so any predictable strategy like this will automatically lose.

3. It is possible to design the game so that what might, at first glance, appear to be a classic full defense action, is actually something different once you consider the interaction with the other rules. For instance, in Burning Wheel, at first glance some of the individual combat maneuvers such as Block appear to be full defense actions which would act strictly as losing combat maneuvers. But this assumes you can only perform one action at a time, which is only true for slow characters. Fast characters can have multiple actions in a round that are performed simultaneously. And performing Block and Strike actions simultaneous is a totally different type of action from full defense; it is more akin to the standard attack action in other games.

Next, I shall list some of the reasons why a classic full defense action, despite being a “losing” combat maneuver, can be effective and desirable in a variety of specialized tactical situations. These situations are typically the primary mechanical reason for including a full defense action in a game.

1. The most obvious situation is when you are under attack and you are unable or unwilling to counter attack or escape, so all you can do is try to wait things out. Perhaps you are trying to survive while you reason with a violent opponent, or you're waiting for someone who has gone berserk to calm down and regain their reason, or intangible poltergeists are throwing things at you and there is no other action you can take.
In many game rules, if you are trying to escape, you are better off spending your entire round moving rather than attempting a full defense action. But in games where you can't substitute your attack action for increased movement, a character who is trying to escape will instead want to substitute his attack action for a full defense action. And if the full defense bonus is very large, it may be better to move more slowly and have an extremely strong defense.

2. You are temporarily unable to attack due to the tactical situation. For instance, in fourth edition D&D, if you are immobilized and you have no ranged attacks, you may find it worthwhile to go on total defense until you are allowed to move and attack again.

3. To wear down an opponent with expendable resources. If the enemy is throwing one use attacks at you, or they are expending endurance at a rapid rate, you may wish to use full defense, knowing that you will have an advantage later in the fight when your opponent has expended his abilities and you have not.
The opposite of this is when you have a powerful maneuver of your own which you have expended, and you are buying time to recharge it.

4. To tie down a very powerful opponent. If you are attacked by an opponent who is much more powerful than you, it might be worthwhile to go on full defense and try to survive long enough for your allies to finish up what the other enemies and come help you out. The idea is that if the opponent's actions are more effective than your own actions, it is beneficial for you to perform a full defense which costs both of you a large portion of your effectiveness. The key to this, and some of the following reasons, is that even though you pay a cost for full defense (the fact that you can still take damage and your target can’t), if the reduction in the effectiveness of the enemy’s action is more significant than the lose of your entire action, you come out ahead.
Some similar to this is the situation in which you have temporarily got yourself in a bad matchup with an opponent you cannot handle, and you need to wait for your allies to come rescue you.

5. If you simply outnumber the opponents, losing actions costs your site a lot less proportionately than it costs the other side, so if you know exactly who they're going to attack, it can be worthwhile to have those people perform full defense while everyone else smashes the enemies at full strength.

6. When you are personally outnumbered, and you can perform a single full defense action against all of the enemy attacks, it may be favorable in terms of action balance for you to sacrifice some actions in order to make a much larger number of enemy attack actions less effective.

7. If you are simply waiting for a certain event to occur, an event which will either end the fight or make you much more powerful, then you have a vested interest in making the fight go longer and you may be interested in taking full defense. Whether you actually do may depend on whether it is more effective to use full defense or to attack the enemies in order to reduce their numbers and thus the amount of damage they cause.

8. If your character has very strong passive abilities and very little attack ability, you may wish to take full defense just so that you can survive long enough to gain the full benefit of your passive abilities, since your attack abilities don't matter much anyway. For instance, if you are playing the “coach” and all you do is give tactical bonuses to the other characters.

Thursday, July 16, 2009

Analysis – Let it Ride rule from the Burning Wheel

In the roleplaying game the Burning Wheel, there is a rule called “Let it Ride” that states that when you have a lengthy, multipart task which requires a certain skill, you should only have to roll the skill check once, and that skill roll is applied to every part of the extended task. Today I’m analyzing this rule and the context behind it.

On the positive side, I can totally see where this rule is coming from. The author mentions that it is directed against the concept of “roll until you fail.” This is a good way of putting it, I have experienced and hated that very same problem myself.

The problem here involves lengthy skill uses which take up considerable "screen time" and involve many sub-elements. For instance, trying to sneak into an enemy base involves sneaking past many areas with sentries or other dangers. Each time, there is logically a chance that the character would be spotted. Indeed, in the movie, there would be a bit of suspense as the character tries to sneak past each individual area where he might be spotted. So it is probably natural for the GM to want to call for a stealth skill check each time the character does something that risks getting spotted.

Unfortunately, when combined with the ordinary skill check rules used in a normal role-playing game, this can easily go disastrously wrong.

The main problem stems from the fact that the probabilities assigned to a skill check usually assume that the check will only be performed once. The GM is expected to determine a difficulty rating according to how hard the check seems to be. So a highly skilled character might have a 70% chance of succeeding in a "hard" skill check, for instance. This is okay when the hard skill check is to quickly repair a badly damaged sports car; since the individual steps aren't very interesting and quite possibly would occur "off-screen", the GM would probably call for one check and see if it succeeds or fails. But in the example of sneaking into the enemy base, the GM might decide it seems like a hard thing to do, and call for 6 hard skill rolls. But this disregards the fact that since failure in any of those roles of essentially means total failure, you have to succeed all 6 times, and that is much much harder than succeeding once. Now your chance of success is only 12% instead of 70%.

Not only is this excessively difficult, but the whole process is very arbitrary. The difficulty of the task ends up depending on how many sub-tasks the GM decides to split it into, and there is no telling how many of these there will be. This can even mean that if the player is good at role-playing and describes his actions in a more thorough and interesting fashion, the GM will think of more opportunities to call for skill checks, and the chance of succeeding will drop. Not much fun at all. I can recall playing games where you just knew there was no way the GM would allow you to succeed in a multi-part self check, even though the GM probably wasn't aware that this was what he was doing.

Even if the GM is fully aware of this problem, however, and wants to make the individual rolls easier, there are further issues. Unless the GM has considerable mathematical sophistication, determining how much easier to make the individual rolls is difficult. After all, there are no guidelines in the game for how to adjust difficulties based on number of rolls required for the check. It would be all too easy to over compensate or under compensate. Especially when you may not be sure how many rolls you are going to end up requiring beforehand. Also, the kind of adjustments required would depend upon the type of dice rolling used in the game.

Trying to convert to making numerous skill checks with a tiny chance of failure is just awkward. There isn't a lot of granularity. If you are making skill checks on d20, for instance, the chance of rolling 3+ 6 times in a row is 53%. Improving the skill check to 2+ increases the odds to 74%. And the next step up is 100%. This means that there is no way to map the many different success probabilities the characters might have on their skills; whether your normal chance of success is 8+ or 5+, the closest you can get to the same probability when rolling 6 times is 2+ either way. You certainly can't easily use a formula like add +6 to your skill bonus, as small variations in skill bonus or difficulty number would mean major changes to the overall chance of success.

But getting the odds correct still leaves a further problem. Rolling many checks, each of which has only a small chance of failure, is not necessarily as exciting as one might like. Rolling a d20, and trying to get 3+, means that a roll of 3 and a roll of 19 are pretty much the same thing. It feels odd, like you aren't really demonstrating your skill, but rather rolling dice to see if your character screws up. When you're rolling for tiny sub tasks, it is hollow to succeed extremely well in one sub task when failure in the remaining sub tasks are just as likely to make it a totally moot point. While if you “Let it Ride” and let one skill roll cover the entire task, it is much easier for the GM to interpret the overall quality of the roll in determining the amount of success you achieve.

For all of these reasons, I think the “Let it Ride” rule is a considerable improvement over the alternative of “roll until you fail”. My only complaint is that I still feel it is pretty far from the optimum rule for complex skill uses. It goes too far the other way. When you have a multi-part skill check with many possible points of failure, you either fail right up front or not at all. As I mentioned earlier, in an actual movie or book every point of failure would be a point of suspense, and you can never be sure whether the entire operation will succeed, or if not, at what point it will fail. But when one skill roll covers everything, once you succeeded in one task, you automatically succeed in every subsequent task – not very dramatic. Of course the difficulty could increase, but if you fail the check because of this, you may feel less like you failed and more like the GM suddenly pulled a dirty trick on you. Of course, the GM could have every task become more difficult than the last, but that means the GM is really “cooking” the adventure in a very specific way. And that it runs head-on into another problem, which is that if you know your roll is low or high to begin with, you can take advantage of this in illogical ways - retreating because you know you are bound to fail the next check, or taking all sorts of extra risks because you know your roll is so high you can't fail.

I think the best solution to this kind of thing is a much more elaborate system for resolving complex “skill challenges”, something like the superb Dramatic Skill Resolution system in Torg. Indeed, the Burning Wheel itself has a very simple version of such a system. But this is a difficult area in which the state-of-the-art in game design is still under development, I don't think any existing skill system I know of would really hit the “multi-part infiltration” scenario totally on the head.

Thursday, July 9, 2009

Game Rule Goals, part 3

Continuing my discussion of the various possible goals of game rules. The truth is, the goals which I've really thought about and considered for a long time and wanted to describe are those of realism, genre simulation, and entertaining game mechanics. But as I started writing this series of articles, I felt I needed to try to give fair coverage to the goals of games which seem to be trying to meet goals which were not one of these 3.

The next possible goal of a game rule or game mechanic is novelty. One of the reasons to create a new game mechanic for a game, rather than reusing a game mechanic used in older games, above and beyond any specific benefits the new rule might be trying to achieve, is just the fact that the game mechanic is interesting purely because it is new and distinctive. Making your game seem new and distinctive could be valuable in marketing a game.

Another aspect of game rules is consistency with other rules. I'm not sure whether I should classify this as a goal or a constraint, in fact I'm not sure I've made a good distinction between the two. It is a generally good thing in games to make elegant and consistent game rules. But it certainly comes to mind that I've seen games which place an extremely high value on the goal of "universality", of making sure that every possible situation is covered by an extension of the basic universal game rules, with as little possible modification of these rules to fit the specific situation. The idea of having some universal rules that cover everything might seem similar to a minimalist approach, but the examples I'm thinking of are quite different. In the old game DC Heroes, practically every object or situation was giving a measurement in terms of AP’s. In many cases this seemed unnatural and made the corresponding rule seem more complex and harder to follow. But ensured that every situation could be described in a way that it was covered by the basic universal rules of AP’s.

Finally, while I’m on the subject of purposes of rules, one of my favorites is game balance. Certainly when I make game rules, game balance might not be the overall purpose of the game, but many of individual rules have the purpose of making sure the various aspects of the game are correctly balanced with each other, with no options that are excessively good or bad.

So in summary, the game rule goals I've covered are:

1. Realism
2. Genre Simulation
3. Self Simulation
4. Entertaining Game Mechanics
5. Minimalism
6. Atmospheric Game Mechanics
7. Novelty
8. Universality
9. Game Balance

I don’t really claim to be putting together a conclusive list here, and my criteria haven’t really been rigorously thought out, but I wanted to put some ideas up for discussion and refinement.

Now, my own great passion is for making game rules with the goal of genre simulation, with a secondary focus on making entertaining game mechanics and maintaining game balance.

What I often find interesting is the interplay between the various goals. When trying to make a perfect game, the “simulation” goals (realism, genre simulation, and self-simulation) are somewhat exclusive - you need to decide what it is you are trying to simulate, if reality and fantasy work differently you can't simulate both at the same time. But genre simulation, entertaining game mechanics, and game balance are things I would all want at the same time, but in many cases it is very difficult to make a rule which optimizes one goal without interfering with other goals.

For instance, I think fourth edition Dungeons & Dragons has really ramped up the entertaining game mechanics and game balance, but at some cost in terms of believability (the simulation aspect). For instance, consider the paralyzing touch of a ghoul. It is very difficult to create a convincing mental picture of why a partially paralyzed character is unable to move from his space but maintains his full agility and combat prowess. But it sure is a whole lot more fun for the player than having his character rendered totally helpless for the entire combat. I think it was overall a good change, but I'm still tempted to think that, ultimately, I'd like to create a rule that is also fun and balanced, but which makes more sense as part of a fantasy story.

Thursday, July 2, 2009

Game Rule Goals, part 2

Before I go on discussing game goals, I'd like to discuss a couple of goals that I am not considering to be the kind of goals that I am discussing. One is the goal of making the game fun. This is practically a universal goal of every game, but it begs the question, "what is it that actually makes the game fun?" The differing goals I’m discussing are each for the purpose of making the game fun from a certain point of view. The second is the goal of playability. If playability means making the game easy to play, then for the purposes of my discussion I would describe it as a constraint rather than a goal. After all, if your only goal were to make a game that is easy to play, you could make a game that was infinitely easy to play by making no game at all. Trying to make a game easy to play is only a challenge when there is something else that you are trying to achieve with the game.

A different interpretation of the word “playability” is what I am getting at with my next major goal of game rules, which I found difficult to describe succinctly. I think "entertaining game mechanics" is most descriptive, though “gaminess” is more concise. This means that playing the game mechanics according to the rules is just intrinsically entertaining to do, regardless of the role-playing context. An example of what I mean here is that a lot of modern “Eurogame”-style board games seem very strong on entertaining game mechanics. Compared to more straightforward older games, a lot of the modern board games have ingenius, clever game mechanics that are fun to play and may have very little to do with the ostensible theme of the game.

The role-playing game that I always thought brought entertaining game mechanics to the forefront was Torg. An element that comes to mind is that of approved actions. This rule gave you a strong in-game bonus for performing nonviolent combat actions such as tricking, taunting, or intimidating the opponents, instead of attacking the opponents. This was cool and different and a lot of fun to do. What I think is interesting to mention is that this rule, which I always admired and found extremely entertaining, greatly advance the goal of entertaining game mechanics but actually worked somewhat against the goal of genre simulation. The idea of these approved actions definitely fit the cinematic genre of Torg. But in Torg, we were using these actions several times per combat per character, to an extent that was amusing but rather silly. Although at the time Torg was my favorite game, I felt that if I wanted to play an adventure that I was really going to take seriously, I would be better off with one of the earlier, more primitive games.

Although I said earlier that ease of play was not something I would describe as a goal, now I'm thinking I could incorporate this somewhat differently as the goal of "minimalism". My passion is for game mechanics, but many games are really designed on the strength of the source material. If this is the fundamental core of your game, you might decide that you want to emphasize that source material and de-emphasize the game mechanics, by making the simplest, easiest, and most concise game rules that still support the minimum requirements for a set of role-playing game rules. Note that this is quite different from genre simulation. With genre simulation, you are trying to make sure that the tactics and outcomes that follow from the rules match what you would expect to see in an adventure of the genre. So when the adventure is done, a recap of the story matches, say, a comic book or a movie. With minimalism, the emphasis is more on the state of mind of the players during the game, on making sure the players are immersed in this scenario and not thinking about the rules. The rules may not do much to encourage cinematic gameplay or character actions, but they also don't distract the players. Minimalism seems appropriate for a game that emphasizes pure role-playing.

If you are trying to particularly emphasize the source material, an opposite approach is the goal of “atmospheric" game rules. Instead of hiding the game mechanics, you bring them to the forefront, because fiddling with the game rules inherently brings out some aspect of the mood of the game that you are trying to convey. My example here is the game "My Life with Master", which I recently read. It has a rather humorous set of rules where character actions for your gothic monster servants are based on concepts like Fear, Weariness, and Self-Loathing. It might appear that these rules serve the goal of genre simulation, but on my reading of the rules I would say that the actual effect of the rules upon the execution of the game is mostly random and would do little to make the action better fit that of the fiction the game is loosely based on. Rather, I would say the strength of the rules is more likely that just talking about rolling your Self-Loathing dice is cool and amusing and encourages you to play the game in the style that the rules intend.

(to be continued next article)