Looking at these rules , I came up with a roll expression that emulates the function of the stress die using three parts: /r [[ [A] 1d10<9cs0cf10 ]] * [[ [B] {2 * 1d10ro10!1=1cs1cf0, 1 + 0d0>0}kh1 ]] * [[ [C] 1 + d9cf0 ]] [[ [[ [A] 1d10<9cs0cf10 ]] * [[ [B] {2 * 1d10ro10!1=1cs1cf0, 1 + 0d0>0}kh1 ]] * [[ [C] 1 + d9cf0 ]] ]] [A] checks if a 'zero' (i.e. a 10) is rolled; if one is, the entire roll expression resolves to equal 0. [B] checks for initial ones being rolled; if any are, part [C] is multiplied appropriately. [C] is a roll between 2 and 10.