Why are most computer games no more than 16v16?

Question

From a programming/network point of view, what are the reasons why there are very few/no larger scale games than 16v16?

There are some 32v32 games but these are seeming exceptions to the rule.

Answer 1

Quite simply, scaling is hard and/or expensive, and O(n^3) is usually a pipe dream. For a game of 2v2, and a naive communication algorithm, you need each computer to communicate with ((2*2)-1) = 3 other computers (not counting some sort of connection mediation server), which comes to ((2*2)!/2) = 12 connections altogether ; likewise, for n versus n players, each computer needs to communicate with ((n*n)-1) computers, which comes to (n!/2) connections altogether.

That becomes ridiculous rather quickly, and other approaches are needed, such as "all players communicate with a central server, which provides them with updates". That is slightly more scalable, but only up to a point. Calculating state for 64 players and communicating with them (and keeping the game state synchronized, even through short disconnections!) isn't exactly simple, especially for games where latency matters (e.g. FPS).

Having massive server farms (with huge pipes to the net) which are dedicated and customized for this, can help, but it's expensive (that's a large part of your WoW subscription); if one of the players' computers is doing this work, lags will become drastically more apparent - both for lack of processing power, bandwith, and latency.

Answer 2

I presume you are talking about mostly first person shooter game, as MMO game supports more than 32 players online at the same time.

From a programming/network point of view, there are no reason that most computer games are no more that 16vs16. A common server can handle the load without problem, and bandwidth wouldn't be a problem.

It's really a game issue. Game that have more than 32 players is more chaotic that nothing else.