The time it takes to decide on the appropriate parameters of a given mechanic. Some RPG mechanics have few and/or very simple parameters for resolution. For example, if a system has twenty maneuver options, then it will be slower to resolve than one which has only two -- even if other factors are the same.

This is related to two similar timing terms, Search Time and Handling Time. The latter two were cited in Ron Edwards' essay "System Does Matter". However, Decision Time was not included there.

References:

• Human factors in game design (rgfa, Feb 1995)
• System Does Matter (1999)
• John Kim's RPG System Design Page
• Time (The Forge, Jun 2001)
• Does Rules-Light Equal Speed of Play? (The Forge, Dec 2004)