(last updated: 09/25/18)
Most of what you can do in response to an attack is purely defensive; that is, there is usually no chance of the attacker being damaged due to a reaction. However, it is possible in certain situations to turn the tables on an attacker and use your own attacks as a reaction! There are four situations in which this can occur. All four situations use the same syntax: 'interrupt < # > = < attack > '.
Counters: Counters work against Physical and Throw attacks as well as Physical projectiles. If the counter succeeds against an attack, you take no damage and your opponent is struck with your attack. If it fails, you get hit with their attack. Physical projectiles work a little differently. If you succeed at countering one, you take no damage, but neither does your opponent. It is also slightly more difficult to counter a projectile than a non-projectile. See counter for more details.
NOTE: If you have at least one Counter attack, you must have the Counter ability.
Reflects: Reflects work against energy attacks (Chi or Psi) as well as any type of Projectile. They work much the same as Counters, except that when you reflect a projectile, the projectile attack goes into its thrower's defense queue with a significant speed boost, and they must now handle it as if you threw it. See 'info reflect' for more details.
NOTE: If you have at least one Reflect attack, you must have the Reflect ability.
Projectiles: When you are attacked by a projectile attack you can interrupt that attack with a projectile of your own. If you succeed the interrupt roll, your projectile will collide with the incoming projectile and there will be a contest of power based on the power levels and the related Offense stats behind the projectiles. If they come out to roughly equal, your projectile will negate theirs. If yours is more powerful than theirs, you will overcome theirs. If yours is weaker than theirs, you will simply slow their projectile (Reduce its over all power) and then get hit by it. Note that it is possible to fail your interrupt roll and still get a glancing hit. When projectiles glance, the power level of your projectile is reduced before the two are compared. It is still possible to overcome, negate, or slow the projectile with a glancing hit. In your 'check' output, you will see 'S' if your projectile will only slow theirs, 'N' if yours will negate theirs, and 'P' if your projectile will overcome theirs.
Pokes: If you lack Counters, Reflects, or projectiles, you're not fully left out in the cold. You can use -any- attack as an interrupt. However, if the situation does not match one of the three described above, what occurs is best known as "poking". If your interrupt succeeds, you will receive reduced damage from your opponent's attack, but they will receive full damage from yours. Pokes have a reduced chance to succeed effectiveness compared to Counters or Reflects, due to the improvised nature of the poke. However, pokes with the PRIORITY effect have at least better if not equal odds to succeed compared to Counter and Reflect.
It should be noted that if you use an interrupt as your reaction, you MAY NOT make an immediate action. You must pose only the interrupt. You have already attacked your opponent pre-emptively, so it counts as both a reaction and an action.
You can set a "default interrupt" to show your chances in the 'check' command. To do so, type
@set me=defaultint:< interrupt >, where
< interrupt > is the full name of the interrupt. If you have style, you can set up a different "default interrupt" for each mode by doing
@set me=defaultint1:< interrupt> and
@set me=defaultint2:< interrupt >.