Melee is a simple attack that does minimal damage, but is effective if you're conserving ammo, or if you just want to feel the joy of beating the crap out of someone. It also works if you need to break something, like a window.
Not the weapon of choice, especially while in a gun-down with a certain commando with ammo. Good if you're almost or completely out of ammo, and you happen to be staring down that commando.It's better than nothing, but always go with an alternative if you have it.
Melee is not completely useless, however. It can be used to hit people from behind walls, and against single enemies it guarantees a kill should the first hit be successful since the enemies are locked in a perpetual stun-lock.
- Melee attacks do not require ammo, and can be done with any weapon.