You do not recruit. You build, and they turn up.

There is no recruitment screen and there is not going to be one. What lives in your dungeon is decided entirely by what you have built, how well you have built it, and whether the conditions to keep them are still true.

That inverts the usual order of operations. You do not decide you want a particular creature and go and get it — you build the thing that attracts it and wait.

What follows from that

• A creature leaving is feedback about a room, not about the creature.
• Build the support rooms before the ones that attract. Somewhere to sleep and something to eat come before more arrivals.
• The treasury is what makes heroes come down at all. Building it bigger is a decision about how much attention you want.

It stops when you look away

The simulation freezes the moment the app loses focus. There are no offline earnings, deliberately — nothing is accruing while your phone is in your pocket, so there is nothing to come back and collect and no reason to feel behind. Closing it costs you nothing.