can someone explain the resist pain spell to me. is it all or nothing? if i have five boxes of damage and score three successes, does the spell do nothing?

Don't have my books on hand, but my Shadow Sense says yeah, it's all or nothing.

If you had 5 boxes of damage and have 3 hits from Resist Pain you only take penalties from (5-3=2) 2 boxes worth that apply to wound modifiers.

If two mages in the same team have it they can negate (some of) the drain panelties on each other more effectively than casting on themselves.

The part to notice in the spell's description is where it says, "reducing the penalties" and not something like 'negating' or 'eliminating'

but the resist pain spell text states that if damage is increased beyond the spell's effect, it dissipates. does that just mean that anytime you take damage after the spell is cast, it dissipates; or that if you have more damage than the spell would resist, it dissipates immediately?

There is no line of text that says it is all or nothing.
[QUOTE=SR4 pg. 200-201]Resist Pain allows the subject to ignore the pain of injuries, reducing the penalties from Physical or Stun damage. Each hit on the Spellcasting Test removes the effect of one box of damage from each of the subject's Condition Monitor tracks.]
There is more but that is the heart of it. Other details are that it is Mana, Touch range, Permanent (removes modifiers for a set of injuries until they heal), and Drain of (Damage value)-4.

Now you can only cast it once per set of injuries, so no second chance to eliminate all the modifiers, and you may have to cast at force equal to the total boxes of damage, but every success negates 1 box per success, not just all or none if you dont get a number of hits equal to force.

Ill try and work up some examples.

This question was answered in the FAQ and they recommended an all or nothing approach. You cast Resist Pain at the desired level and it works until you get 1 box over that and then it dissipates. You can even guess and cast Resist Pain at a desired level before you take damage but, again, if that damage goes over, the spell dissipates.

I would do it so that it doesn't dissipate it just negates a certain amount of pain. I seems silly to have the spell drop like that unless you loose concentration because of it. Now it should be noted that it is pointless to cast this unless you had more then a -2 because you will be taking a -2 for concentrating already.

Also I don't think that you can use it to effect drain. Drain is not the same as pain and it is a magic side effect. That is why I don't think that you should be able to use pain editor on drain either.

Resist Pain must have a Force equal to the number of boxes you have on you. It allows you to ignore a number of boxes equal to the number of hits on the spell casting.

So if you take even one box of damage in excess of the Force of the spell, the entire effect collapses. But the spell isn't all or nothing as to its effect on the damage on you.

-Frank