> while in their own domain

There's a certain poker quip which I like to use and apply to other contexts, such as active investing: "If you look around the table can't tell which player is the sucker, you're the sucker."

In other words, beware entering into a game where the rules ensure somebody will be victimized. This is especially true when many of the existing denizens spend much much more time and effort and finagling than you'll ever want to match.

"A strange game. The only winning move is not to play." -- W.O.P.R, War Games (1983)

All too often I look over at other tables and see that the suckers are friends and family.