Constitution

A character's Constitution (Con) score encompasses their physique, fitness, health, and physical resistance to hardship, injury, and disease. Since this ability affects the character's hit points and chances of surviving such tremendous shocks as being physically reshaped by magic or resurrected from death, it is vitally important to all classes. Some classes have minimum allowable Constitution scores.

Explanations
Hit Point Adjustment is added to or subtracted from each Hit Die rolled for the character. However, no Hit Die ever yields less than 1 hit point, regardless of modifications. If an adjustment would lower the number rolled to 0 or less, consider the final result to be 1. Always use the character's current Constitution to determine hit point bonuses and penalties.

Only warriors are entitled to a Constitution bonus of +3 or +4. Non-warrior characters who have Constitution scores of 17 or 18 receive only +2 per die.

The Constitution bonus ends when a character reaches 10th level (9th for warriors and priests) - neither the Constitution bonus nor Hit Dice are added to a character's hit points after they have passed this level (see the character class descriptions).

If a character's Constitution changes during the course of adventuring, their hit points may be adjusted up or down to reflect the change. The difference between the character's current hit point bonus (if any) and the new bonus is multiplied by the character's level (up to 10) and added to or subtracted from the character's total.

System Shock states the percentage chance a character has to survive magical effects that reshape or age their body: petrification (and reversing petrification), polymorph, magical aging, etc. It can also be used to see if the character retains consciousness in particularly difficult situations.

Poison Save modifies the saving throw vs. poison for humans, elves, and half-elves. Dwarves and halflings do not normally use this adjustment, since they have special resistances to poison attacks.

Table: Constitution
* Parenthetical bonus applies to warriors only. All other classes receive maximum bonus of +2 per die.