Duty rig is 2:1 so if you’re on duty for 12 hours you’re guaranteed to make at least 6 hours credit. Hopefully you’re scheduled to block more.
Trip rig is 4:1 so if you’re away from base for 100 hours on a trip, you’re guaranteed to credit at least 25 hours. Hopefully you’re scheduled to block more (I’ve never had a trip with such low credit that the trip rig kicks in but it’s nice to have). It kind of protects you from the company building very inefficient pairings.
Yes you get these protections if you’re awarded a trip while on reserve.