[emillang1000]

That may have been a house rule for d6s.

The Munchkin Bag of D6s was never given an official rule, so there are dozens (maybe hundreds) of house rules recorded on this site in the Munchkin section of the Forums for those dice. Your friend may have just been using one of those rules.

Either way, the basic rules as-written for Munchkin do not involve rolling any die except for deciding who goes first, determining if you successfully Run Away, or when a card makes specific mention of rolling a die.