You searched for bonus experience
1. bonus experience
You can earn up to 1000 bonus experience from group members when they
complete quests, and up to 4000 bonus experience from expeditions. Each
completion by a group member reduces your quest cap by 100 experience, and
your expedition cap by 250 experience. For example, if your current
expedition cap is 4000 experience, it will decrease to 3750, 3500, 3250, and
so on as members complete expeditions. If your quest/expedition cooldown is
running and you successfully completed (not failed) your last
quest/expedition, your cap will not decrease for the duration of the
quest/expedition cooldown timer (however it will continue to decrease if you
are in a pause room). To restore your bonus to the maximum, you must
complete a quest or expedition yourself. The minimum bonus you can receive
is 50 experience for quests, and 150 experience for expeditions.