Magic the Dungeoning...

Its Magic, with sorta RPG/DnD flavoring.

Each player chooses an avatar (Legendary Creature, and Class) This card persists throughout. Avatar toughness works like armor, reducing damage you take. Blocking with your Avatar gives the attacker a Trample like effect. And your Avatar can never die.

Each player, chooses cards from their "Class pool", as well as adding lands to support you, to create a deck.

DM, sets out creature encounters, and each creature has its own mini deck. Each main creature, works similar to an Avatar.

Works similar to Archenemy, but with much smaller decks, and repeated encounters.

At the end of an encounter, you must sacrifice permanents to retain any permanents cast during or before the encounter, equal to half their total CMC. (Both lands and tokens can be sacrificed to pay this "Persist" cost, and half of your tokens are sacrificed regardless) Your avatar doesn't cost anything.

You also win prize cards, pulled from enemy decks, that can be shared any way you like between players. You may edit your deck between encounters, and you may also trade in 3 prize cards, to pull 3 cards from your class pool, and keep 1. You may also trade in 3 cards to pull 3 lands from your class pool, and either keep 1, or 2 basic lands from the pull.

Every turn during an encounter, you may choose one recovery step during your end phase. Draw one card from your deck, Send 2 random cards from your graveyard to your deck, or DM chooses 5 cards from your graveyard, and you choose one to send to your deck. At any time if you have no cards in your deck, you must do a recovery step. (So yeah, you have a much smaller deck than usual and cards are regularly recycled.)

Obviously this needs work and fleshing out, but it could be a VERY fun way to play some light hearted MTG in a more casual setting, with friends.

I'm also trying to see if this might work with untap as well (to allow cost free play)