GMs are often in a careful balancing act in many games. As a participant in the game, their job is to make sure that the games have to be:
The first two parts are easy, but it’s the third one that complicates things. It’s one thing to challenge your players, and it’s another to use your GM powers to figuratively piss into your player’s cornflakes.
As a GM, my job involves providing conflict for the players. All the grueling fights, the dastardly deeds, loathsome treachery and vile atrocities are committed for one single gameplay goal: to make the characters look like even bigger heroes by giving them the challenges that will shape and define their legends.