['< sod > also traditional in the genre is the eventual demand on players to team up with others in order to progress at the optimal rate. this sometimes forces players to change their own real - world schedules in order to " keep up " with the game - world. a good example of this is the need to trade items to achieve certain goals, or teaming up to kill with a powerful enemy. { { citation needed | date = april 2010 } } < eod > < sod > also traditional in the classic genre is the eventual demand on players to team up with others in order to achieve progress at the optimal rate. this sometimes forces players to change their real - world schedules in order to " keep up " with the game - world. a good example of this is the need to trade items simultaneously to achieve reaching certain goals, or teaming back up to kill a truly powerful other enemy. { { clarify | reason = change from citation needed | and text = is it traditional? | date = october 2016 } } < eod >']