In proper tabletop, ability scores define what a character is innately good at, without training. If he trains in a certain skill or task, his ability scores will always complement it, making him transcend other characters with the same training. Here is what the ability scores do in my game:
STRENGTHThis is the ability that defines the raw, physical power of the character. Their ability to control their body and their movement when under a heavy load, be it a large pack or being hugged to death by an ogre. Their ability to make use of fast and short bursts of strength, such as sprinting, jumping or charging. The definition of body over matter - this ability allows a character to break things with his own hands, be it ropes, doors, or other people. A strong character will be less burdened by a melee weapon they are not used to employing - indeed, they might be as effective with a battle hammer as they are with a tree log, assuming they had no training in both. The ability to attack effectively with a weapon rises with strength, as long as that weapon is heavy enough.
DEXTERITYThis ability defines everything that is coordination. Accurate movements, silent running, well aimed attacks to weak spots, all are affected by dexterity. A character with high dexterity may be able to dodge blows while standing on slippery ice, or roll quickly to a standing position after falling off a roof (assuming they don't break their head). Such a character may quickly step out of a trap they accidentally triggered, or dodge a surprise attack from around the corner. Melee weapons made for critical attacks that bypass defense, such as daggers and rapiers, benefit from dexterity. All ranged weapons benefit from this ability, but heavy bows may penalize one's aim if one's strength is too low. Hand to hand fighting that focuses on hitting weak points also benefits from this, though it requires special training to be effective. It is a somewhat animalistic ability, sharpening one's reflexes as well as senses.
CONSTITUTIONPlayers are used to thinking about constitution as "That HP ability", and I would like to change that. Constitution doesn't only set the amount of attacks one can take before fainting, especially in games that have no HP number like this. To put it simply, constitution is one's ability to survive, to adapt to harsh environments, to resist pain, hunger, lack of sleep, weather and more. One may even use this ability for combat, purposely ignoring an attack to make use of an opening his enemy wouldn't otherwise have. Constitution sets one's resistance to stun effects (even magical ones) and to disease, and sets the recovery rate from wounds. It also defines one's ability to function under physical stress for long amounts of time.
INTELLIGENCEIntelligence is the ability to learn things, gain knowledge, and apply it. It defines one's analytic abilities, to understand new information quickly and break it down to useful rules. It defines one's memory and ability to reach conclusions based on a large amount of information gained at different times. This ability enhances any kind of research, be it looking for clues in books or searching for a key in a cluttered attic. Because of the nature of Arcane Magic, it also enhances spell effects (As they require research and application to prepare), amount of spells known and the most complicated spell one can learn that is within their power to use. Battle tacticians use intelligence to analyze countless previous battles they have studied, and make decisions on the spot. Some swordsmen rely on their brains and muscle memory rather than strength, their attacks perfected to the most effective physical form by rigorous training. Learning languages, sciences, or crafts is also governed by intelligence.
WISDOMWisdom is the ability to perceive the world, understand what is perceived and act upon it. It is more an ability of one's senses than of their body- but less how 'sharp' their senses are and more how quick they are on the uptake that something doesn't fit. It allows reading facial expressions and slight intonation changes to understand the true intentions of one's rival. It lets the character read between the lines of everything in the world, allows them to quickly notice things that deviate from the picture their mind expects them to see. It bestows upon the player a deep, intuitive understanding of the world's works, even on topics they are not expert in. Because of the nature of Divine Magic, wisdom enhances the effects of Divine spells, and the amount of divine energy one can exert without resting. This ability allows one to make quick decisions on the spot by perceiving the situation, rather than studying it. Some warriors rely on the understanding of their body and the body of their opponent, rather than strength or reflexes. Their attacks target weak points that are both physical and psychological, weakening their opponents in more ways than one. These combat styles are rather exotic, and require devotion of body and mind to be effective.
CHARISMAThe dump stat, because it doesn't affect combat at all, right? Hey, I'm not judging. You are free to drop your charisma to 8. Just remember this:
Charisma is not good looks. It is not flowing hair, six pack, chiseled chin. It is not bright blue eyes, long eyelashes or big bouncy boobs. Charisma is presence. It is confidence. It is the aura one radiates when entering the room. Charisma is a stranger's wish to trust you, even though they've met you an hour ago and you're asking the impossible. Charisma is bending others to your will by words alone. A huge barbarian warrior is scary because he is huge and barbarian, sure. But his ability to intimidate, that is make someone think they will hurt him if he doesn't do what they say, is not based on any of that. Because intimidation is based as much on believing the intimidator will hurt you if you disobey, as on believing the intimidator will not hurt you if you do what they say. Charisma makes one want to follow someone who's horrible to them, for reasons one can't explain. It is what makes you stop in the middle of the street, your head swiveling to follow a woman in shy, somber clothes but with an aura that threatens to burst out of the seams of reality. Because of the nature of Sourcery and other magic that requires direct control over otherworldly energies, Charisma directly affects spell power of sourcerers, who gain their power from magic in its purest form, and warlocks, who gain their power from demons.
In this game, the ability scores will be rather hard to change, so plan well. Also, if nothing else in your character sheet, I expect your character's personality to be heavily based on the ability scores. I have yet to meet someone who played low wisdom, charisma or intelligence well. Are you up for the challenge?
By the way, I do actually believe in minmaxing. It should be done properly though, and I will call you out if you don't.