Ability Score Roller

For each ability score, 4d6 are rolled and the lowest die is dropped, summing the remaining three (a result between 3 and 18). This is done seven times, and the lowest of those seven totals is discarded, leaving six scores. That whole process is repeated three times to produce three complete sets — pick the set you like best, then assign its six scores to Strength, Dexterity, Constitution, Intelligence, Wisdom, and Charisma based on the character you're building. Choosing a race other than human or half-elf may adjust these scores per your racial ability adjustment table.

Rerolling: a set is flagged as weak if the sum of its six modifiers (before racial adjustments) is 0 or lower, or its highest score is 13 or lower. If all three sets come back weak, you may scrap them and roll three fresh sets instead.