Fighter
The Fighter is one of basic classes almost in every RPG system ever.
Class role
The fighter's primary role is serving as a meat shield and smashing (slicing, piercing, whatever) things both inanimate, living and undead (as well as any others you can possibly think of). Fighters are also traditionally good at physical activities like jumping, riding animals, balancing and drowning under the weight of their own armor. Fighters are capable of casting weeaboo fightan magic in 4E
Notes
Fighter was for some unknown reason considered seriously underpowered in D&D 3.5, up to the point saying "yeah, sure, you can join; we could use a fighter, just don't use any splatbooks" was a most polite way of refusing a request on joining the party.
