Some times I do small games with my friends/outfit like "who get more kills with [insert weapon] in 30 min".
Taken into account that the tracker already shows your kills and with what weapon it would stand to reason a good amount of the coding is already done and can be reused.

Most of the implementation would be done in the website/server, eventually it could be introduced to the client and shown in the overlay.
Another alternative would be to create a stand alone server app that act as a peer-to-peer server, in this case other players would connect via IP address.

"Tournament creation" Use Case:
  1. player goes to the recursion website and selects create tournament.
  2. inserts tournament name.
  3. inserts password(optional)
  4. inserts time to start
  5. selects restrictions(could be "pistols only" or specific weapons)



"joining a tournament" Use Case:
  1. player goes to the recursion website and selects join tournament.
  2. views upcoming tournaments or searches by name.
  3. selects the "join" button on the tournament.
  4. inserts password if required