I'm well aware of the rule that Art/Resource Assets made by the devs prior to the date of the contest cannot be used.
But what about royalty-free assets? For example, assets provided with the DLCs of RPG Maker series, or other royalty-free assets that are obtained/purchased/publicly commissioned online, since those assets are obviously made before the date of the contest.
(Obviously, let's assume I've obtained permission for using those assets for most purposes, including commercial game usage, which should cover the contests.)