Optimal Party Size?
From the text of the 1980 Moldvay edition of Dungeons & Dragons (p. B19):
It is not wise to adventure alone, for the monsters which may be encountered are numerous. It is much safer to go adventuring with a group of people who can help and protect each other. The best size for an adventure party is 6-8 characters, enough to handle the challenges which will be faced, but not too many to become disorganized or to ruin chances to surprise the monsters.
It’s interesting to observe that as time progressed and both editions and iterations of the game did likewise, the practical optimal party size decreased in membership. On the one hand, in terms of rules and systems, this correlates to the expanded versatility and durability of individual characters. In terms of designing for a particular audience, however, I wonder how much of this arose from the fact that, quite often, it’s damned difficult to be able to coordinate the schedules of 7-9 people (that 6-to-8-person party plus the DM). Did the need for fewer players in characters roles emerge because people still wanted to play in smaller groups? Ludic ethnography at work.
(There’s a separate argument to be made that, as editions progressed, individual characters have become less versatile, owing to an expanding skill system mechanic. To a degree, I buy this argument, as the more systems that exist, the less competent an individual character is if he doesn’t possess an amount of aptitude in that system. Particularly among old-school mentalities, the game revolved around rulings as opposed to rules, and clever plans hashed out via conversational give-and-take with the gamemaster superseded having enough skill points to overcome a static difficulty roll. In this case, a “thief” could generally approach any problem, so long as his player could talk through a logical or exciting method of handling that problem. In later systems, when a character faces a trap, he needs a skill score + die roll to exceed the obstacle value of that trap, which makes the game less about problem solving and more about allocating points and hoping the dice fall fortuitously. Naturally, player styles can achieve an optimal blend of these resolutions, but it’s inarguable that those mechanics exist and can thus substitute for critical thought.)
Other roleplaying games have their own twists on the optimal party size. Vampire, for existence, relies less on monsters and fighting physical challenges. Personally, I greatly dislike running or playing in tabletop Vampire games of more than four players’ quantity, because the character construction and conflict resolutions systems don’t have the same niche protections that D&D does, and sharing the limelight comes as a result of story construction rather than environmental challenges. The Storyteller chooses when and where to put a player in the spotlight, as opposed to the cooperative “dungeon.” On the other end of the spectrum, in games like Call of Cthulhu, it doesn’t matter how many party members you have; you’re not taking down an elder god with revolvers and sword-canes. The environmental threats in CoC tend to be more of mystery resolution and incidental conflict.