RAW question

[emeraldstreak]

A power has a trigger "an attack hits you".

The issue is what exactly constitutes "attack hits you": rolling the d20 and checking against defense? Or rolling the d20, then rolling the damage dice and everything else pertaining to the attack?

[Yakk]

Which power? What kind of action is the triggered power/effect?

A Hit occurs when you roll the d20 and beat the defence. But when the triggered aftion evaluates depends on if it is an interrupt, reaction, free or no action (interrupts occur *before* the trigger and can invalidate it. The other three do not; their exact timing of evaluation requires more care)

[emeraldstreak]

Which power? What kind of action is the triggered power/effect?

A Hit occurs when you roll the d20 and beat the defence. But when the triggered aftion evaluates depends on if it is an interrupt, reaction, free or no action (interrupts occur *before* the trigger and can invalidate it. The other three do not; their exact timing of evaluation requires more care)

The exact power in question that made me think about this was Curtain of Steel (a reaction).

[MwaO]

The exact power in question that made me think about this was Curtain of Steel (a reaction).

Happens after the resolution of all the effects of the attack - i.e. damage, effects, etc...

[Yakk]

A citation why it happens *after* an Effect listed *after* the Hit line would be best, MwaO.

[ve4grm]

A citation why it happens *after* an Effect listed *after* the Hit line would be best, MwaO.

Not by my books, but StackExchange was: https://rpg.stackexchange.com/questions/65469/do-immediate-reactions-that-trigger-on-hit-trigger-before-or-after-you-take-dama

PHB reference: "The triggering action, event, or condition occurs and is completely resolved before you take your reaction"

So yeah, after the triggering attack completes.

[Yakk]

So that is ambiguous.

The triggered event is the Hit. The triggering action is the entire power.

Either the Hit completes and then the triggered action occurs (which could occur before the Effect), or the action completes and then the triggered action occurs (which means a later Effect completes first).

We can see this when the trigger is "moves into an adjacent square"; the move into the square completes, but we don't wait for the move action to complete.

So a power that reads:
Ouch
Attack: +22 vs AC
Hit: 3d12+11
Effect: Target is rendered unconscious

Or

Yowie
Attack: +22 vs AC
Effect: Target is rendered unconscious
Hit: 3d12+11

in Yowie's case, Effect occurs before Hit, and in Ouch it occurs after. It is arguable if this trigger occurs between Hit and Effect on Ouch.

Note that this rarely makes a large difference.

[masteraleph]

You don't actually wait for the action to resolve (for example, the Reaction can happen in between melee attacks in a multi-melee attack power), but the Hit does have to resolve. See RC 195-196 for the most updated rules, including a useful example.

[MwaO]

Note that this rarely makes a large difference.

No, makes a huge difference. Turns a lot of reactions into effectively interrupts. A reaction on a hit in particular.

[Yakk]

I don't believe you. Please cite 3 examples where a power without an Effect line is "effectively interrupted" by a non-interrupt power whose trigger is "hit" if the triggered power occurs after the triggering event (the "hit" text finishes evaluation).

Failing that, give me three examples where a power *with* an effect after hit is effectively interrupted. These I believe may exist, but are rare.

[masteraleph]

I finally have time to retype the RC text, which should hopefully shed light on that problem:

An immediate reaction lets a creature act in response to a trigger. The triggering action or event occurs and is completely resolved before the reaction takes place.
An immediate reaction waits for its trigger to finish, not necessarily for the action that contains the trigger to finish.

Example: An elder dragon's claw attack power is a standard action that allows to attack rolls against the same target. The dragon faces Fargrim the fighter, who has an immediate reaction (veteran gambit) that is triggered by being hit with a melee attack. If the dragon uses claw and hits Fargrim with the first attack roll, he can use veteran gambit in response to that hit. In that case, the immediate action waits for that hit to be resolved, but does not wait for the entire power to be resolved.

Likewise, an immediate reaction can interrupt movement. Here's how: If a creature triggers an immediate reaction while moving (by coming into range, for instance), the reaction can take place before the creature finishes moving, but after it has moved at least 1 square. In other words, an immediate reaction can be in response to a square of movement, rather than to an entire move action.