Where did the term "vanilla" come from?

i’ve heard the term “vanilla guile, vanilla sagat, etc” in some of these fighting games, namely SF4. But what the hell does the term mean?

Vanilla means the original, unmodified version of a game. It’s a term that originates from PC gaming. For example, people will refer to Quake 3 as vanilla Quake 3 as opposed to OSP or CPMA. Each of those have different rulesets, the later two being mods of the base game.

Problem is, a bunch of unfunny idiots applied it to Street Fighter 4 and then cornily started calling subsequent iterations “chocolate” or even dumber “strawberry.”

Vanilla software - Wikipedia, the free encyclopedia