Nippon: Zaibatsu · Board game rules
How does player count affect replayability?
Quick answer
This isn't covered in the rulebook as "replayability," but player count changes many setup quantities and space limits, which affects variety each game.
Details
The rulebook doesn't discuss "replayability" as a concept, but it does specify numerous player-count-based variables that change the game's feel and options each session. For example, the number of available standard Factories differs by player count (2/3/4 of each type) [p.4 — SETUP], and if using the Late-Game Factories module, 3/4/5 late-game Factories are added [p.5 — SETUP].
Worker pool size and Worker Queue rows also scale with player count, changing hiring dynamics [p.4 — SETUP]. Additionally, the number of Ship spaces per Destination (2/3/4), Train spaces per Region (3/5/7), and Influence spaces per Local Market (2/3/4) all vary with player count, directly affecting competition for these resources [p.12 — SHIPS ACTION][p.13 — TRAINS ACTION][p.14 — LOCAL MARKETS ACTION]. Common Goals module setup also scales the number of goals per Period (1/2/3) based on player count [p.5 — SETUP].
In a 2-player or 3-player game, players may also choose which spaces to occupy in a Local Market (rather than being restricted to specific positions), and the 2nd Influence Scoring value is unavailable in 2-player games, altering scoring dynamics [p.14 — LOCAL MARKETS ACTION][p.18 — INFLUENCE SCORING].
If you're asking about something more specific — such as how module combinations (Late-Game Factories, Common Goals) or Solo mode affect variety — the rulebook does cover those setups separately [p.20 — LATE-GAME FACTORIES MODULE][p.20 — COMMON GOALS MODULE][p.20 — SOLO MODE].