ToME: the Tales of Maj'Eyal

First, the air counter either drops too quickly is or inadequately documented. Air is lost at a rate slightly faster than 1 unit per turn as measured against the rod of recall onset time on a character with no speed modifications. I had more than 40 air when I activated the rod in Lake Nur and suffocated. It is possible this is intended but poorly expressed behavior, but if so I feel it a poor design choice, particularly since the gap is small enough to not be noticed when not tracking air use against something like recall time.

Second, the suffocation effect is not cleared by recalling from a zone without air (Lake Nur level 3 alternate) into a zone with air (Maj'Eyal map). Either this is recall related or suffocation deals damage before checking for the availability of air. In either case this is a problem, either with recalling or with the behavior of suffocation being misleading as to time to death.

The rate of air loss depends on the terrain you're in. Most water tiles reduce air level by 5 per turn, while most walls/solid rock reduce it by 20 per turn. In addition, having a sand wall collapse on you, immediately takes away 30 air, in addition to suffocating you for -10 per turn for being buried in sand.

Air is one of the first things checked each turn (before teleporting) so if you're very close to suffocating and then teleport, you can still die.