In a tabletop game, a murderhobo is a player who murders NPCs
indiscriminately. This is normally derogatory, referring to a player who totally ignores quests, dialog, backstory, trade, world building etc.
The term is most common with
Dungeons and Dragons, but it can be applied to most RPGs where the player is allowed to kill most quest-giving NPCs and NPC traders. E.g. Elder Scrolls, Fallout, Divinity
original sin.
DM: The sad little orphan girl tugs at Steve's trenchcoat to get his
attention, and ask for help saving her pet dog from...
Steve: I'd like to roll a strength check against strangling the orphan.
Dave: I call dibs
on the dog.
DM: You murderhobos
disgust me.