Nightlock
From Gloria Victis
Nightlock is an anti-griefing mechanic designed to limit players’ ability to cause unopposed harm to castles during the lowest activity hours of the night. During Nightlock, spawning siege equipment is limited, and siege equipment does half damage.
Any structure damage or destruction that occurs during Nightlock will be reverted as soon as Nightlock ends, so activities such as burning entire cities to the ground are not effective when done during Nightlock.
Any siege preparations in progress at Nightlock will immediately fail, and no new ones may be started.