MTG Salvation

Setup and Default Behavior
Each player has a separate Quest Deck, containing only Quest cards. When the game starts, everyone shuffles their Quest Deck and puts the top card of it onto the battlefield under their control.

At the beginning of a player's upkeep, that player may sacrifice a Quest he or she controls. If they do, they put the top card of their Quest Deck onto the battlefield. If a player controls no Quests to sacrifice, he or she may do this without sacrificing a Quest.

Quest Counters and Victory Points
Each Quest has certain conditions that, when met, put quest counters on them. These are generally formatted as triggered abilities.

Quests also have a "Store" ability, templated as Store N--COST. This means (COST, remove N quest counters from this Quest: you gain N victory points.)

When a standard Quest leaves the battlefield, all quest counters on it are lost--so storing at appropriate times is part of the strategy!

The Quest Card Type
Quests are not permanents. They exist on the battlefield, and thus can be destroyed, gained control of, exiled, etc.--but ONLY by abilities that specifically affect Quests.

Some Quests have triggered or activated abilities. These work like normal.

Quest Subtypes

Some Quests have a subtype called Ongoing (or maybe "Indeterminate" or some other name?). These do not have a Store ability. Instead, they continue gathering quest counters, and whenever they leave the battlefield, those counters are stored automatically.

Other Quests have a subtype called (for now) Singleton. As soon as a Singleton's trigger resolves, you immediately gain some number of victory points and sacrifice the Singleton.

Quest Interactions
Some cards may affect your Quest Deck--for instance, letting you put another Quest onto the battlefield without sacrificing one you have, letting you search for specific Quests, putting Quests back into your Quest Deck, etc.

Quests do not ever go on the stack. They go directly from the Quest Deck to the battlefield, for example. A Quest changing zones can never be responded to. Once a Quest is on the battlefield, however, some cards may destroy it, exile it, put it back in your Quest Deck, make you sacrifice it, etc. Some Auras can enchant Quests (For example, to make them indestructible, to change their Store costs, to make them un-sacrificeable, to steal them, etc.).

If a Quest would be put into a player's hand for any reason (for example, if it was in your graveyard and something let you bring any card type back into your hand; or if a similar situation put it into your library and then you draw it; etc.), instead that player reveals the Quest and puts it on the bottom of his or her Quest Deck.

Win Conditions
If you're the last player left alive, you gain 10 victory points (number can be adjusted...depends on the environment, I suppose). The player with the most victory points when the game ends wins. If multiple people are tied for highest, the person who won normally wins. If no one tied for highest victory points was the conventional winner, they all win as a group, and any other players lose.