When does a custom game count in fortnite?

I wanted to know how many players count as round

For your stats? A custom game round will never count.
.

Ok and arena points?

After all, no arena points would be unfair, because points could be won artificially.

But everyone got points where they played with 25 people

These are shown in-game, but deducted at the end of the round.

Just like with challenges.

Love from.