Combat logging is disconnecting to avoid the outcome of a PvP fight. On servers that take PvP seriously, it is treated as an integrity issue because it lets someone start or accept a fight, then erase the loss with a logout instead of committing to a retreat, a surrender, or a death.
Most setups solve it with a combat tag. Deal or take player-caused damage and you are tagged for a short window. If you disconnect while tagged, the server either kills you, leaves your body or an NPC in the world to be finished, or blocks the logout until the timer ends. The timer usually refreshes on each hit, so the clean way out is still the normal one: break contact and live long enough for the tag to expire.
In play, this makes PvP feel more decisive. Chases matter, escape routes matter, and healing and positioning become real commitments instead of stalling until you can vanish. It also changes the social temperature of a server, because people are more willing to roam, defend claims, or contest grinders when they trust that a fight will not turn into a disconnect lottery.
Strong rulesets stay strict in real fights but avoid cheap punishments. Good implementations account for obvious crashes, give a brief reconnect window, and avoid tagging you for every scrap of environmental damage. The goal is simple: punish dodging, not bad luck.
