To pre-roll or not to pre-roll?

[Pisha]

I'm running a game tonight, and I'm looking for ways to make combat go more smoothly. One of my weaknesses as GM is that I'm not a rules monkey; I know the combat rules for classes I play often, but since I'm running the monsters now I'm running into rules and abilities that I've never used before!

One idea I had was to, before game starts, roll up a chart of attack and damage rolls, and then just go down the list when combat happens. It would save time at the table, and cut down on things I have to keep track of. However, part of me just doesn't like the idea. There's something just right about hearing the GM roll dice to attack you, and I'm not sure if I want to take that out of the game.

Does anyone have any opinions on the idea of pre-rolling the bad guys' attacks? For that matter, does anyone have any other suggestions on how to keep track of the monsters' zany abilities during combat? (I do write them down, but then I'm trying to keep track of a dozen things at once AND narrate an interesting battle, and I forget stuff...)

[Gnoman]

IF you pre-roll, don't go straight down the list. At least do a D100 or similar (still likely to be less dice) so you don't know what the next result will be.

[Kylarra]

the only time I preroll is if there are npcs on both sides and those rolls are more or less used for npc on npc action.

[valadil]

I pre-roll initiative because there are no choices to be made. You take your roll and live with it. Anything else gives me bad vibes. In particular I'd worry about seeing or remembering results. If I know I have a natural 20 coming up, I'll try to time it with a big encounter power. Or I'll try and compensate for that cheesiness and make sure the natural 20 only comes up on an at-will. I don't like either option and I don't like second guessing whether I'm metagaming or not, so I don't preroll.

[Coidzor]

Pre-rolling spot+listen checks for each encounterable creature (and probably the PCs as well...) is a good idea, as well as pre-assigning everyone initiative counts, generally by rolling.

[Tyndmyr]

The only thing I feel strongly about pre-rolling is loot. Doing that is a *very* good idea.

[Pisha]

I pre-roll initiative because there are no choices to be made. You take your roll and live with it. Anything else gives me bad vibes. In particular I'd worry about seeing or remembering results. If I know I have a natural 20 coming up, I'll try to time it with a big encounter power. Or I'll try and compensate for that cheesiness and make sure the natural 20 only comes up on an at-will. I don't like either option and I don't like second guessing whether I'm metagaming or not, so I don't preroll.

Yeah, this was my other concern. I'd like to think I wouldn't do this, and that my players trust me not to... but it might be best just to avoid that situation entirely.

[NichG]

I always take average damage for monsters and NPCs, except on things like ability damage or energy drain where there's a large variance compared to the result and it really matters.

For something with a ton of attacks with the same modifier (natural attack monsters like a kraken, for instance) I'd just take a subset of representative rolls (it gets 8 attacks, so I make 2 rolls each for a set of 4). This can amplify crits really severely, though. When a crit comes up, treat it as only representing a single attack and roll another die for the rest of the attacks in that sequence.

I think this biases the statistics of the mean result a little bit, but not very much considering the rarity of the event - anyone want to do the math?

[Tyndmyr]

That system should reduce the overall incidence of crits pretty significantly. I'd guess cutting them in half or more.

I do use average hp for mobs, usually. It's easy. Attack rolls are generally less problematic. I have enough differently colored D20s to be able to roll essentially as many attacks at once as I can fit in my hands.

[PetterTomBos]

I think this biases the statistics of the mean result a little bit, but not very much considering the rarity of the event - anyone want to do the math?

You end up with:

chance of crit =p

Normal : E(#crits) = sum(p) = 8p

Your system E(#crits) = 2 ( p(one crit) + 2p(2 crits) + 3p(3 crits) + 4p(4crits))

=2 ( p + 2p^2 + 3p^3 +4p^4)

I think. Assuming p is small (no cheese ;) ) you cut the chance roughly in 4. This may be wrong. Im gonna watch How i met your mother with my GF :)

[NichG]

That system should reduce the overall incidence of crits pretty significantly. I'd guess cutting them in half or more.

Edit: Ninja'd on the math.

You're right, its a very big effect. Crit on a 20 goes to a 1.27% percent chance from a 5% chance. Crit on a 19-20 goes from 10% to 2.8%. Crit on an 18-20 goes from 15% to 4.4%. To get 10% you need a 15-20 crit range with this.

So I guess if you triple the crit range you're back to the normal stats, more or less. But then you're not saving as much time on excluded die rolls. Ah well...

[dsmiles]

I only pre-roll in groups with more than 6 players.

[Koury]

I've used pre-rolled d20 rolls before. I basically went to a random roller and had it roll enough to print off a page full of numbers.

I liked having it for things like when the mage Webbed half the enemies so i could point at the bad guys, say "One, two, three, four and five," look down at the sheet and say "Pass, fail, fail, pass and fail." then I'd mark the five rolls off and things kept going.

For anything that mattered, though, I'd roll. PC low on health and being attacked? Roll it. Save or die used? Roll it. Things like that. I was pretty happy with the way it turned out.

[nedz]

The only things I pre-roll are Treasure and sometimes Hide rolls.
Monster HP are averaged.
Everything else happens when it happens, especially since I apply the meta-rule that there is no going back once the dice have landed; i.e. when you roll the dice you make the act.