For example, if the card is a sorcery card, you can cast it only during your main phase while the stack is empty
Cinders are the difficult ones, but even they have fears to be exploited. Illustrated by Daren Bader Standard Not Legal Alchemy Not Legal Pioneer Not Legal Historic Not Legal Modern Legal Brawl Not Legal Legacy Legal Comp
Wildwood Scourge | Illustration by Bryan Sola Hydras is a creature type usually represented by large green X-spell creatures, often found at higher rarities
You can enjoy it with a $40 Commander preconstructed deck or with a $40,000 Vintage deckit's your call
What I mean by that is that these are cards that require a way to physically track which rooms are unlocked in every game, and if you're using something like a die or a coin, those can be bumped onto the opposing room, making things a bit confusing in longer or more complex games