Do you announce roll results?

[Epinephrine]

Setting the scene, when I started this campaign I was not really thinking ahead at how this decision might shape things. I don't know if I always did this, but I've fallen into the habit of announcing to-hit rolls, "27 versus Fortitude" or something and the player looks it up, and say whether it was a hit or not. This was in part because of the variability of defenses. The players all seem to have bonuses that come up sometimes - if they've shifted, teleported, hit a cursed target, in or out of a zone, activated a power, how many milestones we are on (meliorating armour) etc. It was easier to let them track their own bonuses than to try to continually update my numbers.

One party member, the githzerai avenger, would often avoid injury with his iron mind. I didn't pay too much attention to it, it wasn't that big a deal. But it's gotten a bit crazy, as a few players now have interrupting abilities, and they were discussing who should interrupt an attack, since it was going to hit by X, and you don't want to use the power that grants (X+1) on it if you can get away with (X), etc.

Without meaning to, I've altered the way they play and the powers they've selected. If you know all the rolls ahead of time, you can decide whether to interrupt or not based on whether it will work. My impression is that these powers are not meant to be infallible.

Do other DMs deal with this? Do you announce rolls, or ask for defenses? Do you let them know of critical hits before they use an interrupt, or do you allow them to waste them? I ran the last session asking for defenses and it greatly frustrated the players, who complained that the powers aren't any good if you don't know if they'll work. I pointed out that they can have a good idea if they'll work; if it's a high defense, the hit probably isn't by much. If it's a low defense (say, the dump stat defense on a character) a +2 will be much less likely to change it to a miss. So you don't throw a small bonus to the goliath to help him avoid a fireball (he's hit on a 2), but if they hit his Fortitude, it might be worth doing.

[Tegu8788]

I go ahead and ask if a number hits a defense. Now, my players never had any semblance of strategy, but if deciding which power they'd use for interrupts became a problem, I'd give them a time limit or require them to declare beforehand if they plan to use it.

[Kimera757]

I announce the numbers ahead of time. 4e is slow enough that I don't want to make players play the "guessing game".

I also think 4e has far too many interrupt powers like the one you described. I think WotC developed very interesting classes and powers, but often took the "short view", resulting in problems such as not stopping the bloat of off-turn abilities even after complaints started.

Feel free to put limits on discussions in combat. For instance, maybe only the player is allowed to discuss things in out-of-game terms, to cut down on things like "I'd like you to move to this square so I can have space for a combo next round".

[Epinephrine]

Feel free to put limits on discussions in combat. For instance, maybe only the player is allowed to discuss things in out-of-game terms, to cut down on things like "I'd like you to move to this square so I can have space for a combo next round".

Oh yes, there's far too much of the whole, "no, you can't stand there, so-and-so will need that space for X" I try to keep them from optimising every bit of positioning, since it's meant to be a melee...

[EvilAnagram]

I tell them roll results, but I don't allow discussion of Immediate Reactions or Interrupts.

[Kurald Galain]

Holding back roll results will slow down your game for no good reason.

You may want to restrict the amount of interrupt powers per character though, because they also slow down the game (and frankly it's all too easy and mechanically solid for high-paragon characters to have four or five interrupt powers).

[Laserlight]

In our game, the DM announces the roll and the player tells whether it hits or not. That way the player can get some good out of his interrupts. It's no fun blowing an encounter, or worse yet a daily, to find the DM rolled a 20--and the game is about having fun.

Other players can use interrupts or not, but cannot discuss them.

The rule at our table is that in-character comments go with initiative. If my Initiative Roll 17 sorcerer says something, the initiative 7 healer will get a chance to reply before the Initiative 27 Paladin who has already taken his action this turn.