Everyone has their preferred number of players, and of course some games are better at different player group sizes. For myself, I've long since settled on 4-5 PCs as the optimal mix of varied opinions, good energy / impetus, varied PC capabilities and ease of fitting at a table with everyone's gaming junk, and I've found that's held true for pretty much every RPG I've ever played. That's a sample size of 1, but I've never had the impression that I'm alone in this: in my experience, this is a common table size.
What surprised me, then, when diving headfirst into old-school D&D was how comparatively enormous the standard group size once was. Looking at the image to the left, that's a pretty beefy party by modern standards. But it's quite typical for the play environment of the day. Let's take a look at the various old-school rulesets, starting with OD&D:
The game is ideally for three or more adult players: one player must serve as
the Dungeon Master, the shaper of the fantasy milieu, the “world” in which all
action will take place.
(That having been said, one commenter observed that the DMG's NPC party generator on p. 175 assumes 1D4+1 characters, "with men-at-arms or henchmen to round the party out to 9".)
Mentzer's Basic has largely the same statement as the DMG, while Holmes is even more minimalistic, stating only that at least two players are required.
So while OD&D goes for an upper boundary, and the other rulebooks of the era go for a lower one, it falls to the official adventures to get a feel for how TSR's designers actually wound up playing the game. A look at the old-school adventure line-up (through 1982) for D&D and AD&D is quite revealing:
- A1 (Slave Pits of the Undercity): 6-8 players
- B2 (Keep on the Borderlands): 6-9 players
- B4 (The Lost City): 6-10 players
- C2 (The Ghost Tower of Inverness): 5-10 players
- D1-2 (Descent into the Depths of the Earth): 7-9 players
- G-1-2-3 (Against the Giants): “The optimum mix … is 9 characters”
- I1 (Dwellers of the Forbidden City): 6-8 players
- I2 (Tomb of the Lizard King): 7-9 players
- S2 (White Plume Mountain): 4-10 players
- S3 (Expedition to the Barrier Peaks): 10-15(!) players
- S4 (The Lost Caverns of Tsojcanth): 6-8 players
- U1 (The Sinister Secret of Saltmarsh): 5-10 players
- X1 (The Isle of Dread): 6-10 players
- X2 (Castle Amber): 6-10
players
This wasn't universal, though it was pretty close. Not all modules have suggested player sizes, while B1 was for 3-6 players, specifically including NPCs. L1 was unusual in having a recommended floor of 2 players, but still had a high end of 8; similarly, N1 ranged from 4 to 7 players. C1 has no specified size, but does note that if the party has fewer than 5 players then the recommended player level for the module increases, so there's a minimum assumption of 6 players there.
A quick look at some of the better adventures published in Dragon in this period wasn't as fruitful, as many don't give suggested party sizes, but 1981's The Temple of Poseidon (Dragon #46, by future TSR employee and co-designer of Star Control Paul Reiche III) was recommended for 7-10 players and that same year's The Chapel of Silence (Dragon #50) was for 6-9 players (6 2nd- to 3rd-level characters, with a possible 3 1st-level characters as backup). Larry DiTillio (of Masks of Nyarlathotep and Babylon 5 fame) had his adventure Chagmat appear in 1982 (Dragon #63), and it was for 6-8 characters. As such, you're seeing DMs in this period matching the official TSR environment (or at least, the DMs whose adventures were being singled out as the best by TSR and accepted for publication).
Overall, the pattern is very clear: the minimum player size is almost always 6 players, and the maximum averages out to 9. This also matches was Gygax wrote on ENWorld in 2004, where he said that for OD&D "it was assumed that a typical adventuring party would have about 8 PCs plus as many hired men-at-arms".
Play Today
Let's take a look at some of the encounters in Keep on the Borderlands (a 1st-level module):
- 8 kobolds
- 18 giant rats
- 6 2-HD lizardmen (limited to one per round emerging)
- 6 hobgoblins
If you sit down to play Keep with just 4 players with 1st-level PCs, you're going to find it a brutal grind. Double that number, with a retainer or three for backup, and you're in a much better place; the encounters become ones deserving of respect, but beatable.
Couple this with a major shift in expectations—unlike modern editions, an old-school DM is supposed to be a neutral arbiter, not expected to kill PCs (the common strawman of old-school play) but also not determined to keep them alive—and you get a vastly different play experience. (It's also worth mentioning the assumptions underlying combat as sport vs. combat as war).
So while old-school D&D is undoubtedly more lethal than the post-TSR versions, I think a good part of its reputation is due to people playing it today with a set of expectations not shared by its designers.
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In terms of my game Simulacrum, this is why I've based the design on the assumption of 4-5 players. To enable old-school modules like Keep to be played with this ruleset, I've buffed starting PCs: two hit dice to start, two spells for casters, a higher attack bonus available, and D6 HD for monsters (as OD&D did it). Rather than deciding to make PCs more capable, I simply hoped to be able to play some of the old-school modules I own that expected 6-9 PCs with the 4-5 players I prefer. If I expect 4 players to be able to deal with 8 kobolds with roughly the same threat level as Gygax expected, I need stronger PCs out of the gate. Though it might look like it on the surface, they're not coming away with a lead: they're just keeping up.