I've begun the very early stages of testing a wargame.
I have found that I've vastly underestimated the time it takes to play, but this is mostly due to the time it takes to set the game up.
See, I've got a number of different units for a handfull of factions, and a large number of different scenarios that can be played. Each scenario is its own game, and each scenario only uses sub-set of the available faction units. Some scenarios use dozens of units, some only a few.
So while the actual play-time of a small scenario might only be expected to be 30 min, from opening the box to the end of the game is a lot longer. Then, even just counting the actual play time, there is the fact that experienced players might get done in 30 min, while green players might take 2 hours.
What is the conventional way to estimate the time it takes to play? What parts of the game should be included in this estimate? Should I estimate for optimal, average, or conservative values?
Possible time inclusions:
1) Deciding which scenario to play, including variants and choosing sides.
2) Organizing the particular units used in the selected scenario.
3) Setting up the starting conditions.
4) Playing the game, first actual turn to the last turn.
5) Packing everything up.