Gears of War: Judgment features class based multiplayer - a first for the series.
On the COG side the classes are the engineer, soldier, medic and scout. Damon Baird is an engineer, and carries a Gnasher and Blowtorch. His special abilities include deploying a a sentry turret and repairing damaged fortifications. Augustus Cole is the soldier, and carries a Lancer and Boomshot. He can deploy ammo crates and can resupply the engineer's Blowtorch ammo. Sophia Hendricks is the medic, and carries a Lancer, Snub pistol and Stim Gas grenades. She can use grenades to revive downed enemies. And finally Garron Paduk is the scout. He uses the Longshot and the Snub as well as a beacon grenade.
On the Locust side the classes are the Wretch, which can leap over hazards, the Ticker, which can eat fortifications and grenades, the Kantus, which can heal friendly units, the Grenadier, which, you guessed it, specialises in grenades, the Bloodmount, which specialises in melee, the Mauler, which carries a shield, the Serapede, which provides ranges support and the Corpser, which can move underground.
The new Overrun Mode is inspired by Team Fortress and DOTA. In consists of two timed five versus five rounds where one side defends a pair of objectives from the opposing side. As the COG, you protect two sealed Emergence Holes and a Hammer of Dawn beacon. There is progression for the player as well as levelling up of single characters.