The Sten is a British submachine gun featured in some Medal of Honor games. It was famous for its recognizable side-mounted magazine. The Silenced version was common among the allied covert ops, but it had low heat tolerance.
Automatic firing was only advised to use when in extreme danger.
The Sten Mark II appears in Medal of Honor: Underground. It is first found in Amongst the Dead, the second level in the first mission, Occupied!. It is dropped possibly by Fabrice Delacroix, Manon Batiste's and Jacques' resistance fellow. He incorrectly states that enemies use the MP 3008 so her Sten will be compatible with their weapons. The MP 3008 appeared in 1945 as an emergency weapon, so it's appearance is anachronistic with the time period (occupied France). The Germans used captured Sten guns classified as the MP.749. But the MP 3008 really was compatible with Sten magazines, since it's only difference with the Sten is the vertical magazine.
There is also a possibility to see the Sten Mark III in the loading screen after successfully completing a level.
The Sten Mark V appears in the expansions of Allied Assault. In Spearhead it was used by Sgt.Barnes and Foxhound during the Normandy campaign. In Breakthrough Sgt.Baker used a Sten Mark V during the Monte Cassino campaign along with British soldiers. In both games' multiplayer the Sten is available for the British soldiers as a starting weapon. In game the Sten incorrectly called "Sten Mark II" however it is the Mark V variant since the wooden grip and stock.
Sten Mark V in Medal of Honor: Allied Assault: Spearhead
The version encountered in-game is not usable by the player and is exclusive to NPCs. The variant encountered in the game is only seen in the level, Arnhem Knights. The variant behaves in the same manner as the StG-44 and even uses the same firing sounds as the StG-44. The model of the Sten Mark II appears to be an unsuppressed variant. Sergeant Kelso always has one.
In Rising Sun The sten holds 20 rounds, but it's model shows a 32 round magizine.
In the briefing of level 2 of mission "Occupied!" in Medal of Honor Underground, as mentioned above, it is said that the Sten would be compatible with the magazines of the MP 3008. This could have been confused with the MP 38, the earlier predecessor to the MP 40. The MP 40 used a 32-round magazine and 9mm ammunition, so the Sten might be compatible with it.