Defensive pistol matches are run using IDPA rules (
www.idpa.com). Cost is $10. Typically they run 3 stages with no more than 18 rounds per stage (revolver friendly). I usually bring 100 rounds to the match.
Occasionally they run a low-light or no-light stage where you will use a hand held flashlight while shooting & reloading. Gun mounted lights are not allowed by the IDPA rule.
On rare occasions they may run a stage with a backup gun (BUG) to start the stage. BUG's are any small handgun with a barrel 3" or less per IDPA rule, and they ususally start with the gun on the table. You will transition to your main gun after emptying the BUG (usually 5 rounds).