From #openttdcoop wiki
The term Coopetition stands for the idea of bringing a competitional challenge into our cooperative gameplay.
- Two players team up and play versus another team.
- A dedicated server will be set up for this challenge - besides the 4 players, only visitors are allowed. The Server will run on a Nightly version of Openttd, without any additional GRFs loaded.
- The game will begin at a previousely settled date/time.
- The playing time is limited to 8 years (~2 hours). The game will take place from 1959 - 1967 to make upgrading of locos necessary.
- Each team may use a voicecom like Ventrilo or Skype to improve its communication. Its all up to the team.
- A random map will be played.
- In the end, the train income matters. At the beginning of year 1968 the game will be paused and a screenshot of the budgets will be taken.