Helping another player - against their will?

[MunchkinMan]

Unfortunately, there are several cards which dismiss a Monster or end the combat outright, so without a question about a specific card, I can't give you a specific answer. Of the cards that do this, some have to be played by someone in combat, but many don't. However, a player can't jump into the combat of his own volition. He must be invited by the player who initiated the combat. On the other side of the coin, anyone can play a one-shot Item to affect either side of the combat, or a Wandering Monster card along with a Monster, or a Monster Enhancer. None of those activities constitute being a helper, which is a very specific thing: Joining in on the combat and adding your Level and combat bonuses to the munchkin side.