Assuming a compound maximum HP system with a “miscellaneous bonus/penalty” factor (like the one described in #392) is implemented, make it a major trouble for prayer if this miscellaneous factor is deeply negative (e.g. -20 or below).

One possible “trouble” if you are praying is having more than a certain total level/total difficulty of hostile monsters around you relative to your own level. If your god decides you are in trouble from this and decides to fix the trouble, they will teleport you horizontally somewhere else on the level far from any monsters. If the level is non-teleport, they will instead lift you up one level like a potion of gain level would. If that cannot be done, they will not attempt to fix it.

If you pray at low HP with a single hostile monster in the vicinity, your deity might decide to “fix” the problem by smiting them to death.

Being a male Valkyrie is a minor trouble when praying and will be divinely fixed by reverting you to female.

Uncontrolled teleportitis counts as a minor trouble; a god may decide to fix it by removing it, but only if there are no other troubles. If there are other troubles, teleportitis will not be removed.