For me: Either freeform, or bound to class. I hate limiting your player's class/species combos too much and unless you give the oddball (i.e. orc bard or halfling fighter) some other benefit, you will limit what many call "viable choices", especially as many players prefer low-to-midlevel play where you don't see a maxed out stat in a non-optimal combo.
In more detail: this is a very philosophical question. we've had lots and lots of discussions about racial ASI and ability caps and requirements in earlier editions. Let's just say it often descended into a cesspool of semi-political or biologistic themes, and debates about "but mah realism" in an otherwise utterly unrealistic game (from a scientist's point of view at least).
Depending on how you choose to design your game, you make some core assumptions about your characters:
- If you bind it to "race", then humans will be everything and other ones will favor one type of classes over the others. STR bonus? - more martials. INT bonus? All hop onto the wizard train. DEX? Congratz, you've won the ga- err, you got some flexibility but will most likely end up as a rogue, swashbuckler or archer. What you're basically saying is that race X has a much higher population of class/profession Y because of "their genes". All nature, no nurture.
- If you bind it to class, then the character will have that high stat because of training or because this individual has some inborn talent for using stat X, thus choosing the class. Nature or nurture, depending on the player's choice.
- If you bind it to culture, then said culture does value an expression/training of stat X over others. Which is all nurture, no nature. Mechanically, it is basically the same as having it be tied to class, but on a broader (and imo more limiting to the individual player) sense.
In more detail: this is a very philosophical question. we've had lots and lots of discussions about racial ASI and ability caps and requirements in earlier editions. Let's just say it often descended into a cesspool of semi-political or biologistic themes, and debates about "but mah realism" in an otherwise utterly unrealistic game (from a scientist's point of view at least).
Depending on how you choose to design your game, you make some core assumptions about your characters:
- If you bind it to "race", then humans will be everything and other ones will favor one type of classes over the others. STR bonus? - more martials. INT bonus? All hop onto the wizard train. DEX? Congratz, you've won the ga- err, you got some flexibility but will most likely end up as a rogue, swashbuckler or archer. What you're basically saying is that race X has a much higher population of class/profession Y because of "their genes". All nature, no nurture.
- If you bind it to class, then the character will have that high stat because of training or because this individual has some inborn talent for using stat X, thus choosing the class. Nature or nurture, depending on the player's choice.
- If you bind it to culture, then said culture does value an expression/training of stat X over others. Which is all nurture, no nature. Mechanically, it is basically the same as having it be tied to class, but on a broader (and imo more limiting to the individual player) sense.