It's something like:
No res: around 8 damage per turn
1 res: 3-5 damage per turn
2 res: 1-2 damage per turn
3 res: 1 damage every other turn
4 res: safe
These are estimated on my experience. Not thoroughly tested.
IIRC fire immunity only counts for 2 sources of resistance and you still need items to boost the count. Can anyone confirm.
Completed: All Races, All Classes. Twice.
Fastest Run: Dwarf Mindcrafter - 34803 turns. No wand of tele.
Challenge Games: C- CK (stupid ending), Platinum Girdle x10, Westside Story, Team Teleport - illiterate troll barb, Scroll of Omnipotence obtained
ULE - DE Archer