[4] Combat Advantage

[Volomon]

I'm still in the process of figuring everything out, but say an opponent is in a position to grant two combat advantage(s). Do they stack? It sounds like they don't since you can only have A (being singular) combat advantage. At the same time it seems like if there is more than one thing affecting them you should get something extra.

[CarpeGuitarrem]

Nope. You either grant combat advantage, or you don't.

[HMS Invincible]

You can't lower someone's defense very much in 4e, but you can stack penalties to attack rolls. Prone gives -2, long range, concealment, cover, etc, etc. You can lower defense by a feat, and combat advantage. That's it.

[Thajocoth]

Penalties and untyped bonuses always stack, except when they're from the same source. The +2 to hit is of the "Combat Advantage" type... Therefore it does not stack with itself.

The same goes for if, say, you used Illusory Ambush on an enemy to give it a -2 penalty to attacks, then used an Action Point, and used the power again on the same enemy, that penalty wouldn't stack either because it's from the same source (Illusory Ambush). This would also apply if both you and someone else used the same power on the same enemy (or two enemies use the same power on you).

[TheEmerged]

Yeah, combat advantage is like the marked condition in that it's boolean -- you're either granting it, or you aren't. Unlike marked, however, you can easily be granting it to multiple people.

[mobdrazhar]

actually Combat Advantage isn't a penalty on the opponant... it's a bonus on your to hit.

[Swordgleam]

What everyone else said. However, you aren't always granting combat advantage to everyone. If you're granting combat advantage to the rogue and the fighter, there is something extra - they both get +2 to hit you, as opposed to if you were just granting it to the rogue, in which case you can be slightly less worried about the fighter.

It's not a condition like prone or dazed; it's more of a relationship. There are certain things that cause you to be granting combat advantage to everyone, but usually, you just grant it to one person for one reason. If other people have CA on you, it's probably for different reasons.