PBF PREP for Shogun No Katana

[RogerBW]

Dice roller ahoy!

[roll 4d3 - 4] 4d3: 3 + 2 + 1 + 2 = 8-4 20 characters (This thread is for feedback on the dice roller, which is being maintained by @RogerBW on github. Bug reports welcome. Bug reports with fixes even more welcome.)