An arcade beat-em up with a Diablo pedigree; a fast-paced multiplayer first-person shooter; a complex competitive strategy kingdom builder—these are the first shots fired in Facebook's battle to expand its gaming player-base beyond farmers and puzzle-players, with another seven in the chamber for 2013.

Console quality games are a hard sell on Facebook. Each day millions of people log into Facebook to tend their virtual farms or play colorful candy puzzle games, while the hardcore shooters or robot-powered action role-playing games attract daily users in the low ten-thousands. What's it going to take to get…