This rolls six-sided dice for Swedish RPG Eon. Eon rolls work with "exploding" dice, so when a six is rolled, that die is re-rolled, and an additional die is rolled.
For example: I roll two dice. If one result is a six, I do not add the six to my total. Instead, I re-roll that die, and roll a third die. The results of the re-roll and the third die are added to my total - unless I roll a six. In which case I re-roll that die, and add a fourth die to my roll.