Ability Scores of each normal character are 3d6.
On the other hand, after the funnel character has the ability scores of lowest 3 of 4d6.
Why are after the funnel characters weaker than regular characters?
Technically, slightly better than lowest 3 of 4d6. But the real difference is that when you use a funnel to create a first-level character, the adventure serves to select for the best character of three.
