Cambridge University Students' Union elections occur once per year, and include the following roles:
The election is decided by the Single Transferable Vote system. This means every voter ranks the candidates for each role in preference order. For each role rounds occur until their is a clear winner, with the least popular candidate being eliminated. Each round every voter's vote counts towards the most preferred candidate who has not been eliminated (although the vote then counts with a reduced weight).
For voters, this means rank candidates with 1 as the most preferred, and rank candidates who are definitely not wanted as low as possible. There is always a candidate "Re-Open Nominations" (RON).
For more information, see the CUSU elections webpage or email the Pembroke returning officer.