Pick your poison: Defense of the Ancients 2 or League of Legends. The nuances and complexities of the two titles differ, but their core mechanics are similar. You choose a hero and get placed on a map, teamed with fellow players to face off against an identically chosen team of other gamers.
The basic goal of each game is to nuke the other side’s base. However, you can’t just Rambo it: At fixed intervals, your base will release little minions—creeps—that form the raw infantry of your assault. Follow them up the map’s lanes, push forward against defense towers and other players, and your coordinated efforts might win the day.
Even better, matches typically last about 30 minutes—which is just brief enough that your temporary absence from the family dinner table may not raise suspicions.