in an RPG, how many characters should be in the adventuring party?

Examples of some party sizes:
2: Final Fantasy Mystic Quest (note that only 1 can grow, the other one is a temporary character who keeps being replaced, but you have one for every dungeon)
3: Chrono Trigger, Super Mario RPG, also (for some reason) many PSX era and later JRPGs, including most offline Final Fantasies from 7 onward
4: Traditional JRPGs, including Dragon Quest 3-9 (but not original 5), Final Fantasy 1-6 (but not 4), and most other SNES and earlier JRPGs; also Ultima 3 and Avernum series (but not the original Exile games), also seen in Might and Magic 6-7
5: Seen mostly in niche JRPGs, including FF4 (which isn't niche), many SaGa games, Etrian Odyssey series
6: Common in older WRPGs, for some reason, including Wizardry (except 4 and (counting temporary characters) 8), Might and Magic 1 and 4-5, Bard's Tale 1 (if you don't count the monster slot). Also common in Wizardry-likes, including the Elminage series (again, not counting the monster slot).
Some games have even bigger parties.

What party size do you prefer? Personally, I like 4, which is enough for characters to have different roles, but not enough to become unwieldy or to require that characters be overspecialized. (I happen to like hybrid characters, personally, but characters still nee to be different.)

Edit: To clarify, this question is solely about your preference for party-based RPGs: Games where you only control one character do not count as party-based.

one

Six, like in Baldur's Gate, Icewind Dale, Planescape: Torment and Albion
Anything less is just not enough with all those monsters around.

I know there was an old PlayStation game where you could actually pick from 1 to 7 (or more, I can't remember) then go into the dungeon and do whatever it was you were meant to do.

I'd like to be able to choose like that, because sometimes I want one or two super strong people... and sometimes I want a bunch of weaker team-role folks.

actually I'll just settle on 4 like Star Ocean. Which means it needs to be real time skill based combat.

I can't win today! :P

I'm going back to my cave underneath the sea! :D

Maybe it's an RPG about interacting with people in a party.

OT: Four.

Personally, I find it unwieldy when you have a party size that large in a game that tracks individual character positions. (It's not as bad as in a game like Wizardry where your party is essentially one blob and you don't control individual characters, but even then I find that 4 is typically enough.)

Case in point: Ultima 4 tends to slow down and become less fun as you recruit more party members. What makes this problem especially bad is that you *have* to have all 8 party members to beat the game.

Generally I agree with four, but certainly not over five. With five you can double up on your favorite and still be pretty varied.

For some reason i preffer 3 just because of mondschein game german rpg maker game,there are only 3 usable characters there and you fight the enemies standing on bottom screen and attack upper field and the same with hybris rebirth gold or called hybris pulse of ruin in english,but the english version still needs to be completed. You have 3 characters maxium on screen but you can change them though to someone else since they require you to use abilities to get further in the game,also the party in hybris had 11 playable characters. You would choose your attacks from a skill list and use them under number 1-6 the rest is defensive,buffing abilities which you would use with number 7-9.
Was kinda fun using only 3 characters though one mostly for fighting,other for magic and one mostly healing in both games.

I like party of 2 or 4. More than 4 then I run out of character name ideas and if it's too many I stop caring about them.

Four. They's typically how many primary skills there are, and most games are balanced for that anyway. You ever try to divvy equipment for a 6 person game? Not easy.

How about one primary character, with henchmen?

I guess it depends... sometimes you get to build the entire party from scratch (BG2), sometimes you take on new members as you meet them (BG). And it varies with the game itself, so when there are a lot of different classes and skills it might take more party members to "cover the bases" as it were.

Given that, can't say I have a preferred number.

Yes. That's why I love NWN 1 so much.

Depends how many interesting classes there are in the game. Whatever was in Baldur's Gate 2 and Icewind Dale (6?) felt pretty good for those games. I recall I would have preferred to have even one more slot at least for IWD, to try out also a bard character in my party.