Ability Score Improvement is a Fighter feature gained at level 4 in the 2024 SRD. You gain the Ability Score Improvement feat (see "Feats") or another feat of your choice for which you qualify.
You gain the Ability Score Improvement feat (see "Feats") or another feat of your choice for which you qualify. You gain this feature again at Fighter levels 6, 8, 12, 14, and 16.