There are four classes in Brink, but there's a disappointing lack of definition between them. Due to the nature of Brink's maps, classes require constant changing.
Engineers place turrets, plant mines, hack computer consoles and buff the damage and armor of teammates. Operatives sneak into enemy territory undetected. Soldiers plant charges to gain access to new areas and supply teammates with extra ammo. And medics scramble around the map, dishing out health boosts and revival syringes to downed allies.
The lone aspect of character creation that actually affects how you play the game is your body type. Every character begins with a medium body and soon unlocks heavy and light types. Heavy characters have the most health and can carry the biggest guns, but they are also the slowest and least nimble. This makes them well suited to defending key areas or clearing out rooms, but you sometimes have to take the long way around to find a staircase. Light characters have the least health and can carry only small guns, but they are also the fastest and most nimble. They excel at running fluidly around the map and leaping to areas other players cannot reach, while peppering the enemy with gunfire. Medium characters are both nimble and durable, though not to the extent of the other types, and they function as a versatile blend of the other two.With 10 or 11 abilities unique to each class, as well as another 10 universal abilities, there is a lot of room for customizing your battlefield presence.