Each role may be played by one or by many users. Each role can only be played by users in the group specified below. If a group is not selected for any role, user in that group will not be cast in the simulation

TODO: Show total number of users per case

In Automatic casting, only users from these groups will be assigned to the roles. All user from all selected groups will be cast. If all users for one rol are cast before all users for another role are cast, you will b cast as many times as needed to fill out the cases. (You ca change casting assignments here.

In Group casting, users can choose which case to join Users are still restricted by group/role limits set below (e.g. if each case requires three users from group X and two from grou Y, the fourth user from group X to try to join will b rejected.).

In Open casting, users can choose which case and role t join, subject to the restrictions below

TODO: if enroll-type is open, show all groups from the subsite in each role

TODO: Number of users should by greater than 0.

TODO: auto-check all boxes by default