I have been involved for the past couple of decades with a laser game system known in various parts of the world as Zone 3, Darkzone, Megazone, Ultrazone; and a few other names as well.
Zone is different from almost every other sport in that there are three teams in any one game. This makes creating round-robin grids for leagues and tournaments more challenging than for regular two-team sports: creating a grid in which every team plays every other team the same number of times turns out to be difficult, particularly as the number of teams rises.
After the round robin, you may wish to use a Cascade.
It's fairly common to finish a league or tournament with a Finals.
Here is a table of Swede Base Run format grids.
Here's how we fixture Doubles at ZLTAC.