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.

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