Stay is a command that can be given to a minion to make them leave your tribe. When a minion has been ordered to stay they will act like they are from another tribe. Their health bar will turn the yellow-orange color that allied tribes' minions have and there is no way currently no way to get them back after doing this. Stay is a beneficial ability because it makes players less likely to aquire resources due to it having a guard.
Stay is currently bugged at the moment. To get it to show up after unlocking it, you need to unlock another skill or technology so that it shows up. So do not unlock stay at the very end of the technology tree.
Stay Units have the ability to stay on meadows and has guarding as their top priority, their second priority is to collect resources if they are able to. Stay Units after battling a player and if they do go out of the meadow, they will never automatically return, instead they just stay at their last location.
The Stay Units have a script that automatically makes them go out of the meadow if they reach a certain number, it can activate either through conflict (battling) or by pure chance. When they go out of the meadow they will randomly attack whatever is in their way, their sense of direction is random as well, you could even call this Savage Mode because the Stay Units randomly go to locations within the map, and of course it will only end when they all die.
Additionally, Stay Units automatically encircle a campfire, it is unknown if they recover their health if a totem is near the campfire or if they recover their health through their own collected meat.