godan verb (-ru)
to profit from others' conflict; to play both sides
Slang derived from the idiom 漁夫の利 (fisherman's profit), used especially in gaming contexts when a third party takes advantage of two opponents fighting each other.
See also: 漁夫の利
While the enemies were fighting each other, I profited from their conflict and took all the items.
あのチームはいつも漁夫るのがうまい。
That team is always good at taking advantage of others' fights.