All dice are d6 (its the d6 system). For all important rolls, you roll a number of dice, add them all together, and throw a modifier on top (skill rank, equipment modifier, etc). The Wild Die replaces one of the dice, before it is rolled. For example: if you were suppose to roll 4d6+3, you would roll 3d6, the wild die, and then add +3 to the total. Special parts" explodes on a 6 (on a 6, reroll and add). If you roll a 1 on the initial toss of the die , it will take itself and the highest die rolled with it. However, certain rolls never suffer the negative effects of wild die; damage, for example, can explode but not lose dice. Couple of examples (the wild die is the bold one): We roll 4d6 and get: 1, 5, 6, 3 . total is 15 (neither 1 nor 6 appeared on the wild die. We roll 4d6 and get: 2, 5, 1, 1 . Total is 3, because the wild die was a 1 and took the 5 away. We roll 4d6, and get 5, 2, 1, 6 . We re-roll the 6 and get another 6, so we re-roll that again (damn dice are loaded, I know it) and get a 1. Total is 5+3+1+6+6+1= 22 because the 1 was only bad on the initial toss. There, I think I covered all the bases. I think. Maybe. Its late, but I hope this makes things easier to understand.