Survival is the major component of initiative, luck, regeneration and elemental resistances, and a minor component of accuracy.
Hit points are regained based on the square of regeneration, and are independent of constitution and vitality. Magic points are restored at a rate based primarily on Intelligence and partly on regeneration.
The math appendix of the
Beyond Divinity Strategy Guide goes into the secondary stats a bit, and gives some general recommendations on stat point distribution.
There is a typo in the last formula in the 'other secondary stats' section; in the formula for evasion, the second term should be speed, rather than survival.
