At NTRPGC this year, I got to play Tunnels & Trolls with its creator, Ken St. Andre. My only experience of T&T before this was a few runs through solitaire adventures. It seems that we were the first people to play the T&T Free RPG Day adventure. Ken was an enjoyable GM, and we got a sneak peek at the Deluxe Tunnels & Trolls changes.
Perhaps my one apprehension about T&T has been its highly abstract combat system. It seemed to work much better in play than I’d anticipated, though. It seems to smooth out the kinds of imbalances between characters that T&T doesn’t avoid. The “weakest” character still contributed to combat and the “stronger” characters could protect them by soaking up the damage. It also played very quick and got us back to exploring and parlaying with the NPCs.
But, on to the topic at hand: Like D&D, T&T characters have a number of attributes that are generated by rolling 3d6. Ken had us reroll attributes below nine. Since there is an almost 26% chance of rolling < 9, though, that meant a fair amount of rerolling. So, that got me to thinking about ways to do it without rerolling.
My first thought was to use 6+2d6 instead. That would mean the minimum was 8 instead of 9, but...close enough. It does greatly change the probabilities, though. At least it is simple.
Next I considered 6 + (3d6 drop the highest). I was surprised by how close this was to the original 3d6 reroll < 9. It seems perhaps “too fiddly” for T&T, but it seems to get the job done.
This AnyDice plot shows the probabilities for 3d6, 3d6 reroll < 9, 6+2d6, and 6+3d6 drop the highest. Switch it to “graph” and then check out the “normal” and “at least” views.
Note that this ignores the TARO rule: If you roll triples, you get to roll three more dice and add their results. It’d also be interesting to work out the chances of qualifying to be a paragon (all attributes ≥ 12) would be for the different methods.
Whichever method might be used, one question arises: Should the reroll < 9 rule apply before or after kindred (i.e. race) modifiers? I’m thinking: Before.
(Another question about kindred modifiers is whether a character qualifies for a type (i.e. class) before or after kindred modifiers. But Ken said that in dT&T, only human characters have types.)