REC-IM hosts various league sports throughout the academic year. In order to compete, a hall affiliation must put together a team, which adheres to all of the roster rules listed below, and send a registration to REC-IM. Competition for most leagues is split into two divisions per gender: A Division and B Division. These two divisions will have their own regular seasons, playoffs, and championship. REC-IM reserves the right to move a team from one division to another if they feel that they would be better suited in another division.
- A Division
The A Division is made up of more competitive teams. In this division, the players generally have a higher skill level and play at a more adept level. Teams are allowed two varsity players or coaches of that specific sport if they are not in season. The intensity is higher and the emphasis placed on winning is greater.
- B Division
This division is more suited for those who are just playing for the enjoyment of the sport. Teams are allowed a max of one varsity player or coach of that specific sport if they are not in season. Generally speaking, the skill level is a bit lower than the A Division and the intensity is considerably lower.