Any situation to which the following applies:

1. There has to be a chance of failing at a task.

2. The chance at failing is quantified as a chance out of 4, 6, 8, 10, 12, 20, or 100.

3. Anything else that could affect the chance of failing at the task is taken into consideration and assigned a number.

4. Throw dice at someone and run like hell.

Note: I found this node as a nodeshell, and couldn't resist.

I think technically this is a designation applied to a MU* in which a wizards not sporting broadswords and platemail are not automatically beat down. Many (most?) MU*s do not encourage or require a player to actually ACT anything like their character and in many cases, it's quite stupid or considered bad form to actually role-play. A roleplayer friendly MU* is one that does not penalize you for acting like your character would act. Compare to roleplay required.