How Complex Should a System Be?

Designing a game system - the mechanics - from an intentional point, starts with identifying a few things. What stories should the game support? Is there a kind of die you want to use? How many people will play? How experienced is the average player?

All these questions sort of point at the same thing: how should the game feel?

And the thing that will have the most impact on how the game feels is complexity.

Complexity in game rules can be most easily defined as the number of choices presented to the players that are mechanically represented.

Imagine the game as a machine, like a mechanical calculator or engine. The core mechanics are a mass of workings in the center of the table, operated by the game master. Each player has a character - a widget or module of the machine that they can slot into the main structure and make changes. Those characters are, for the most part, the only way to interact with the larger arrangement. They're the tools they use.

The complexity of the characters and the core mechanics must match. Each character tool should have a respective match on the device. Mechanics with which characters can't interact are useless cruft; character traits that have no impact on the mechanics are fluff.

This match in complexity can lean to simplicity, or to sophistication, either way. A simple system with only a few things to adjust is like an old car engine. The characters that interact with it are wrenches. A wrench can only do a few things, but the system only calls for a few things - a match. Sophisticated, complicated systems are like computer networks. The tools to serve and change them are, themselves, smaller computers that require rare knowledge to operate. Without the right tools the thing stalls out. Match.

A mismatch feels bad. Trying to fix a diesel engine with a laptop loaded with diagnostic programs will get nowhere. Likewise, getting a server running with a toolbox full of hacksaws and screwdrivers is going to be a disaster.

So how complex should a system be? As complicated as necessary to make it feel right. Do you want to use hand tools or power tools? Are you trying to build a boat together or optimize a power grid?

The only most important thing, then, is to make sure everything has an impact. No useless tools, no useless sockets. Every choice a player makes - the mechanical ones, anyway, rather than the flavor and backstory - should matter.