Talk:Artoria Pendragon (Rider Alter)/@comment-104.32.101.200-20170809191159/@comment-29893250-20170815103017

It means that he can roll on the selected rate up day. If they were both 4 star, he'd be forced to roll with the whole pool. Since he wants one SR and one SSR, rolling on the rate up day eliminates the one he doesn't want, leaving the whole rate up being used most in his favor.