Here's an interesting perceptual issue in terms of table top RPG's.
If you try and do diplomacy with someone in table top play, and the GM says you can't do a roll, is that him altering the mechanics of the game? Or do the mechanics say he gets to determine if a roll is involved?
Frankly from RPG texts I've always read the latter. But D7 says it's the former.
Dirty Tricks and Randomization
11 hours ago