Improved Point Buy

https://www.5esrd.com/gamemastering/5th-edition-options/

The standard point buy does not allow for stats that go beyond 15. This is because in the standard game, stats raise fairly easily and have a maximum of 20.

This may not be the case in your game. With this optional rule, you can expand your character creation to include stats up to 18, albeit at a greater cost.

In addition, there are different point pools listed to suit the various styles of game play that you may wish to use in your games. A low fantasy game should not have the same measure of ability scores as would an epic fantasy game.

* Standard Fantasy is the default creation set for a typical game, though we use high fantasy.