Challenge Board
The Challenge Board is a section on GTM where 2 people can challenge each other through AI'd battles (similar to tourneys) or a vote challenge (similar to BOTM). When someone wins a Challenge, they gain one Challenge Point, whilst the loser of a Challenge loses a challenge point. The current record of challenge points can be found here.
How a Challenge typically operates
First, a member announces that they want to challenge someone through this thread, with what Weight class (LW, MW, HW and so on) and version of RA2 they want to build their bot in, as well as whether it's a VOTE or a BATTLE challenge.
Then when somebody replys along the lines of "Challenge accepted" or even just a simple "ok lets go", the 2 (The challenge board has a loose rule of 2 people to a challenge, no more, no less) challengers discuss via Personal Message the exact rules of the challenge. Then they search out a host if it's a battle challenge, Dragonfire is a well known Challenge Board host.
Afterwards, they create a thread for the challenge where the challengers show their bots (optional in battles, required in votes) and if it's a BATTLE the host records the bots battling and posts a video of it in the thread. If it's a VOTE challenge, the competitors post pictures of their bot with a poll and whoever gets the most votes wins. Afterwards, the Challenge Rankings are updated with the points won/lost from each competitor depending on who won.
More on Challenge Board rules can be read here