Havoc
From Planetarion Wiki
Havoc: a special game that occurs between the main rounds. There are few rule changes, BUT the tick time is reduced from one hour to something shorter. (for example, ticks were 15 minutes during the round 13 Havoc) Havocs only last a few days.
For the most recent Havoc (after Round 13), all players were upgraded for the duration of the Havoc.
Part of the Round 13 Havoc involved a new type of Havoc: Capture the Flag (CTF). Each galaxy was given special flag roids, and you gained flag 'roids when you successfully attacked the 'roidholder. Gaalaxies were scored as follows: Their own flag was worth 5 points, and any other flags they captured were worth 1 point.