PAX
From Planetarion Wiki
Officially PAX is the name for Planetarion's Round 10. Due to the interim Round 9.5 it was actually the 11th round. PAX introduced a large set of changes, including a whole new codebase and radically different gameplay. Many things are discussed in pre-PAX and PAX terms (the latter being the current style of game). For example, the pre-PAX combat engine was more complicated than the current engine. Combat also lasted up to 3 ticks in pre-PAX rounds.