Free engines

More to explore · intermediate

A free engine produces value off-turn or for no mana. These are the engines that keep paying while you spend your mana and your turn on other things: passive triggers, end-step or upkeep value that you do not have to activate, and effects that fire on events rather than on your main phase.

The count is the number of such engines the deck runs.

Why it matters

A deck with zero free engines is fully tempo-gated: every point of value it generates costs it a card and the mana to deploy it that turn. Free engines break that ceiling — they let the deck advance its board and its card advantage in the same turn, which is what separates a grindy value deck from a pile of individually-good cards.

How to use it

If the count is 0, adding one free or off-turn engine is a structural change, not a marginal one. Look for a card that pays off on an event you are already causing (something dies, something enters, an opponent does a thing) so the value arrives without a dedicated turn.

A note on what counts

The metric counts engines that are free in the lever sense (off-turn or no-mana value). A creature that cheats other creatures into play is powerful, but it may not register here if its value still costs mana to set up. The deck evaluation's deterministic delta shows this honestly, so an "add a free engine" swap whose count stays 0 is a reasonable card that does not move this particular lever.