In Wolfenstein: Enemy Territory, the player can choose 5 different classes. Each has a different task in the team.
Soldier
A soldier's position is at the front of an assault. As they carry the heaviest weapons around, ranging from flamethrowers to panzerfausts (bazookas) and even mobile MG-42's, they will be slowed. They need good protection from their teammates, or they will be an easy target. A soldier uses his power bar a lot. Mortars and panzerfausts use 50% and 100% of the soldiers' power bar respectively, so they can't be fired very frequently. When soldiers gain more experience, firing a mortar or panzerfaust will use less of the power bar (You'll read more about that later). Soldiers are useful for rushing into guarded rooms when wielding flamethrowers, defending an important objective with a Mobile MG-42, or just taking out as many enemies as possible from a safe range using a mortar or panzerfaust.
Medic
A medic is essential for every team. Medics start out with barely any ammo, only one ammo clip for the MP40 (or the Thompson, if allies), some syringes and one grenade. Good medics will be in the line of fire really often, but not really as an assault trooper. He is often busy healing his allied troops. When an allied soldier is wounded really badly, and his health points (HP) fall below one, he can either give up and go into reinforcement line, or he can wait for a medic to revive him. To revive a teammate, the medic has to stand over the wounded soldier, take out his syringe (normally at slot 5) and fire at the soldier. He will then stand up again either with 50 HP, or, if the medic has reached First Aid level 3 (See the Skills page), with full health. To heal other soldiers, or himself, the medic uses health packs. Every health pack heals 20, and costs 25% of the power bar. (15% if First Aid level two is reached.)
Engineer
As Engineers are needed for most objectives, they are unmissable in any team.