Racial attribute modifiers do not exist, except as suggestions for what is typical.
Characters are built on 32 points instead of 27.
Characters may buy a 16 stat for 12 points.
Human (non-Variant) gets +4 points.
The good thing is that it greatly expands the realm of viable builds, as you aren't locked into the races that have an attribute bump in your class primary. It does, however, somewhat change the balance between races, and thus might cause a balance issues. Most don't seem problematic, but at least one comes to mind immediately: mountain dwarf medium armor proficiency was previously useless (every class that wants +2 Strength already has it) but dwarf wizards in half-plate might be an issue.
Like you said, there would be balance issue if you are doing a strict codified variant for racial ability scores. I think that this is probably something that is best dealt with on a case by case basis between the DM and the player.
If the player wants to play a Dragonborn cleric, and wants to swap his charisma bump for a wisdom bump, then he should ask his DM and they can come up with any additional changes that might be needed.
Now for dragonborn, this probably isn’t going to cause any issues, but there are some races with really OP racial traits, but lackluster ability scores like the yuan-ti pureblood (poison immunity and advantage on all saving throws vs magic????). Yes I would like to change that to a +2 strength +1 constitution race please DM. It’s not because I want my fighter to be OP, I just really want to play a snake person fighter. There needs to be a conversation there for sure.
Edit: Basically the game has been balanced around the different races having specific ability scores. Changing this messes with game balance, so it needs to be dealt with on a case by case basis.
So, I was thinking of a variant for attributes:
The good thing is that it greatly expands the realm of viable builds, as you aren't locked into the races that have an attribute bump in your class primary. It does, however, somewhat change the balance between races, and thus might cause a balance issues. Most don't seem problematic, but at least one comes to mind immediately: mountain dwarf medium armor proficiency was previously useless (every class that wants +2 Strength already has it) but dwarf wizards in half-plate might be an issue.
Any other obvious or not so obvious pitfalls?
Like you said, there would be balance issue if you are doing a strict codified variant for racial ability scores. I think that this is probably something that is best dealt with on a case by case basis between the DM and the player.
If the player wants to play a Dragonborn cleric, and wants to swap his charisma bump for a wisdom bump, then he should ask his DM and they can come up with any additional changes that might be needed.
Now for dragonborn, this probably isn’t going to cause any issues, but there are some races with really OP racial traits, but lackluster ability scores like the yuan-ti pureblood (poison immunity and advantage on all saving throws vs magic????). Yes I would like to change that to a +2 strength +1 constitution race please DM. It’s not because I want my fighter to be OP, I just really want to play a snake person fighter. There needs to be a conversation there for sure.
Edit: Basically the game has been balanced around the different races having specific ability scores. Changing this messes with game balance, so it needs to be dealt with on a case by case basis.
Generally speaking, it think these house rules are pretty good.
As mentioned there is some case by case balancing that may need to be done for races with strong traits.