Dungeon Crawl Classics
Ability Scores over 18 are as follows:
19: +3 ( +2 Wizard Spells)
20: +4 ( +3 Wizard Spells)
21: +4 ( +3 Wizard Spells)
22: +5 ( +3 Wizard Spells)
23: +5 ( +4 Wizard Spells)
24: +6 ( +4 Wizard Spells)
The highest modifier any ability score can provide is a +6 (Most commonly with the Luck score).
Strength: Physical power for lifting, hurling, cutting, and dragging. Your Strength modifier affects melee attack and damage rolls. Note that a successful attack always does a minimum of 1 point of damage regardless of Strength. Characters with a Strength of 5 or less can carry a weapon or a shield but not both.
Agility: Balance, grace, and fine motion skills, whether in the hands or the feet. Your Agility modifier affects Armor Class, missile fire attack rolls, initiative rolls, and Reflex saving throws, as well as the ability to fight with a weapon in each hand.
Stamina: Endurance, resistance to pain, disease, and poison. Your Stamina modifier affects hit points (even at level 0) and Fortitude saving throws. Note that a character earns a minimum of 1 hit point per character level regardless of Stamina. Characters with a Stamina of 5 or less automatically take double damage from all poisons and diseases.
Personality: Charm, strength of will, persuasive talent. Personality affects Willpower saving throws for all characters. Personality is vitally important to clerics, as it affects the ability to draw upon divine power and determines the maximum spell level they can cast, as shown on table 1-1.
Intelligence: Ability to discern information, retain knowledge, and assess complex situations. For wizards, Intelligence affects spell count and maximum spell level, as noted on table 1-1. For all characters, Intelligence affects known languages, as described in Appendix L. Characters with an Intelligence of 7 or less can speak only Common, and those with an Intelligence of 5 or less cannot read or write.
Luck: “Right place, right time;” favor of the gods, good fortune, or hard-to-define talent. Players would be well advised to understand the goals of gods and demons that shape the world around them, for they are but pawns in a cosmic struggle, and their luck on this mortal plane can be influenced by the eternal conflict that rages around them.