The following is derived from a Steel Warrior thread on the subject. Examples are therefore based on warrior numbers, but should be roughly applicable to other classes.
1 attribute point in CON yields:
- 3.75 HP
- 0.1 to all resists
A dwarf, at max CON of 378, can therefore achieve 1417 HP and 37.8 resists. This represents a gain of 615 health and 16.4 resists for the attribute points spent (based on a minimum of 214 CON).
At the lower end of the spectrum a goblin at max CON of 255, can only hope to get 956 HP and 25.5 resists. This represents a gain of 615 health and 16.4 resists for the attribute points spent (based on a minimum of 91 CON).
In other words, the gain is the same but the end result is significantly different.
Taking Armour Into Account Edit
Itchtakhta swamp armour is a common pre-APW tanking set (with or without the Rhaz helm). In full Itchtakhta, our hypothetical dwarf and goblin (representing either extreme of the CON range) are buffed to the following values:
- Dwarf: HP from CON total 1758, resists 46.9
- Goblin: HP from CON total 1297, resists 34.6
Based on armour stats as follows:
- BP: 0 CON
- Legs: 12 CON
- Shoulders: 0 CON
- Feet: 12 CON
- Girdle: 12 CON
- Hands: 15 CON
- Helm: 14 CON
- Underlay: 12 CON
- Wrists: 14 CON
= 91 CON total = 341 HP, 9.1 resists from CON
The above obviously does not include 'native' HP already on the armour, which incidentally comes to 1244, for a total HP gain of 1585 to any race.
- __% chance to totally resist a X based spell.
- Seems to be roughly resist x 0.04?
- __% chance to partially resist a X based damage effect.
- Resist x 0.1
- __% (__% on a partial resist) mitigation of incoming X based spell damage.
- Resist x 0.1 (doubled for partial)
- Difficult to find a consistent number that works for this value, on some characters seems to be resist x 0.09, but not on others.
- __% mitigation of incoming X based melee damage.
- Same as total spell resist.
- May be capped at 10%: when fully buffed, total spell resist rises above 10% but melee mit locks at 10%.
Where 'resist' is the value displayed on the main character window, and where 'X' is any of fire, cold, physical, mental, arcane, spiritual. All vs equal level at 50.
Based on this, every 10 points in CON yields:
- 0.04% chance to totally resist a spell
- 0.1% chance to partially resist a spell
- 0.1% incoming spell damage mitigation (.2% on a partial resist)
- 0.04% incoming melee damage mitigation
- Dwarf (46.9 resist in Itchtakhta armour): 1.8%, 4.6%, 4.6% (9.3%), 1.8%
- Goblin (34.6 resist in Itchtakhta armour): 1.3%, 3.4%, 3.4% (6.9%), 1.3%
Resistances seem to be calculated differently for lower level characters. For example, a level 1 warrior with 40 CON gets 8% chance to total spell resist vs equal level (CON / 5). By level 10 this seems to have shifted to roughly CON / 100, which still holds true at lvl 20.
Class or race does not appear to affect the formula for calculating resists (though obviously base/max CON is affected).
It may be a mistake to try to relate resists solely to CON. DEX has an effect on spell resist, with 0.1% chance added for each attribute point spent. However, changing DEX doesn't seem to update the resist chance on the main character window, so this may be calculated separately.