Not all role-playing game have fumbles. In fact, I suspect that were an intrepid soul to catalog every RPG—a daunting if not impossible task—, more RPGs would lack fumbles than possess them. However, many games have optional rules for fumbles for those players who like them, and many games will have specific elements that'll see a deeply flawed attempt yield consequences worse than mere failure despite lacking a general rule for fumbles. So, yeah, while the games you've played have had fumbles, fumbles are by no means a universal.
Possibly the Original Fumble Mechanicsoriginal fumble mechanics
While I'm no role-playing game scholar, Chaosium's Runequest (1978) apparently included fumbles, at least as early as 1980 (which is the version I extracted from my shelf, dusted off, and cracked the binding of when I flipped through it). Runequest (1980) has the following section:
(It took a moment to find the page number: they're on the outside upper corner of each page. Pro Tip: If you're laying out a book, don't do that!don't do that!)
Speculation: A Possible Reason for Fumbles
Speculation: Why fumbles exist
ManyFans of role-playing gamersgames may view the fictional reality of the role-playing game creates as a heightened reality, which I'll call for convenience reality-plus, let's call it. In In actual reality—the one we're really in—most of us are in, like it or not—, very little that happens mattersmatters in the grand scheme of things. In reality-plus, however, everything that happens atduring the tablegame matters, and spectacle is expected, for good or ill. And spectacle during even everyday tasks can lead to comedy or tragedy that is a hallmark of reality-plus.
IfFor example, while training with his Great Axe [sic], Argath of Sartar chops off his own head, that's. That's a thing that probably would not happen in actual reality—very few real-world highly trained axemen accidentally decapitate themselves—, but that sort of spectacle is expected in reality-plus because things happenArgath of Sartar is important, and his training took place during the game.
A game with fumbles does nottends not to mirror reality because the random number generator that's used has so little granularity. A highly trained archer might shoot himself in the head with an arrow or some other absurdity, but that's will notthat surely won't happen once every 100 arrows he fires in actualactual reality.! Were itthere even a 1% chance of every attempt leading to catastrophe in our reality, archery ranges would be sad, sad places, littered with the dead, naked, and injured.
But in reality-plus if those 100 arrows are fired while they matter launchingwhile they matter—during the actual game—, one of those hundred arrows is likely to cause the archer's armor strap to break or make him fall and twist his ankle (those are average results on the Runequest (1980) Fumble Table). That happens in reality-plus because that's spectacular.
That possibility of spectacle makes the game, for some, more interestingmore interesting rather than more ridiculousmore ridiculous. It turns the game from what some considermay view as a mere boring simulation into a drama, albeit, in this player and gamemaster'sfan's opinion, in a really forced way.