Complex sentence: He frequently assumed the role of the Game Master (GM), a role he has likened to writing a webcomic, but his interest in the hobby lapsed until 2000 when Wizards of the Coast released the third edition ruleset for the game.
Split into simpler sentences: He frequently assumed the role of the Game Master (GM), a role he has likened to writing a webcomic,. His interest in the hobby lapsed until 2000 when Wizards of the Coast released the third edition ruleset for the game.