This is a very tricky problem. We want dice that generate outcomes of two fair dice but no 7s, and every other outcome having the same relative probabilities. Note the generating function (x + x^2 + x^3 + x^4 + x^5 + x^6)^2 - 6x^7 has no nontrivial factors, so we must get creative. My first solution was to consider the generating function x^2 + 2x^3 + 3x^4 + 4x^5 + 5x^6 + 5x^7 + 4x^8 + 3x^9 + 2x^10 + x^11 = (x^6 + x^5 + x^4 + x^3 + x^2 + x) (x^5 + x^4 + x^3 + x^2 + x). So we can do it with a standard 6-sided die and a 20-sided die with 4 each of 1,2,3,4,5. If you roll a 7 or more, add 1. My solution is completely different from anything mentioned in the article. I actually like my solution much more, as it uses two readily available Platonic solids. You don't even need to renumber! For the D20, you can divide the face number by 4 and ceiling, or mod 5 and add 1.