Beat 'em up (also known as brawler) is a video game genre featuring melee combat between the protagonist and an improbably large number of underpowered enemies. These games typically take place in urban settings and feature crime-fighting and revenge-based plots, though some games may employ historical or fantasy themes. Traditional beat 'em ups take place in scrolling, two-dimensional levels, though some later games feature more open three-dimensional environments with yet larger numbers of enemies. These games are noted for their simple gameplay, a source of both critical acclaim and derision. Two-player cooperative gameplay and multiple player characters are also hallmarks of the genre.
The first influential beat 'em up was 1984's Kung-Fu Master, with 1986's Renegade introducing the urban settings and underworld revenge themes employed extensively by later games. The genre then saw a period of high popularity between the release of Double Dragon in 1987, which defined the two-player cooperative mode central to classic beat 'em ups, and 1991's Street Fighter II, which drew gamers towards one-on-one fighting games. Games such as Streets of Rage 2, Final Fight and Golden Axe are other classics to emerge from this period. The genre has been less popular since the emergence of 3D-based mass-market games, but still some beat 'em ups adapted the simple formula to utilize large-scale 3D environments.