The original arcade version of Capcom’s 1991 Street Fighter II had eight playable fighters.
The selectable roster consisted of Ryu, Ken, Chun-Li, E. Honda, Blanka, Zangief, Guile, and Dhalsim. Players could choose any of these eight world warriors, while four additional characters—Balrog, Vega, Sagat, and M. Bison—served as non-selectable opponents in the original version.
A common mix-up comes from later editions. Street Fighter II: Champion Edition, released in 1992, made the four boss characters playable, bringing the roster to 12. Later revisions added further characters and changed the game’s title, so counts quoted for the broader Street Fighter II series do not always describe the first arcade release.
The original Street Fighter II was important not only for its roster but also for its character-specific move sets, six-button control layout, and competitive match structure. Those features helped establish the conventions of the modern arcade fighting-game genre.