In 3.x, rapiers were meh. They have crit range 18-20 which was good only if you planned to get improved critical feat or enchant it with keen property. It's only martial weapon with d6 damage you can use with finesse and get to 15-20 crit range. Regular short sword was just slightly worse than rapier (19-20 x2 crit) and it was half the price
Elven thinblade and in PF1 Elven curveblade were go to weapons for dex based finesse melee characters. Thinblade was 1d8 18-20x2 finesse weapon and Curveblade was 1d10 18-20x2 two handed finesse weapon (so you got your 1.5 str to damage).
So basically, if you were a rogue, the best options were a rapier, or a more rapier-y rapier. That's part of what threw me into this chain of thought. I previously envisioned rogues using mostly short swords, or depending on the edition, maybe a long sword, or maybe they have a variant trait that gives them more martial weapons. But with 3e they turned into Errol Flynn.
Someone said rapiers started with AD&D... I looked it up, they are not in the 2e PHB. Any rapier-type weapon, presumably a 15th century transition weapon, would probably be a "long sword," two words, a Shakespearean-era designation for a typical, one-handed arming sword of any length. DMG 2.5 also does not describe rapiers, and does not mention them in the Renaissance equipment lists, only "early guns." I know they appeared in
A Mighty Fortress, which had several fencing proficiencies, in fact.
Obviously, in a fantasy world, this comes down to preference, but from an aesthetic standpoint, most of the weapons are 12th to 15th century, not modern, like a rapier. Flintlock guns (barely) predate the rapier. I've seen anime shows where they have warriors and mages and dragons and such, but they also have bubble tea and cat clocks, which I am fine with as it's own thing, but I don't think of as the usual genre for D&D. But maybe I've just gotten too old, and rapiers and flying ships and clockwork cannons are pretty standard for this type of fantasy now.
