Mystery Key
Artifact — Equipment
When equipped creature deals combat damage to a player, sacrifice this Equipment. If you do, draw three cards.
Equip 
(: Attach to target creature you control. Equip only as a sorcery.)
- CMC
- 2
- Mana cost
- Color identity
- U
- Rarity
- uncommon
- Set
- The List
- Price
- $0.08
- EDHREC rank
- #16553
Mystery Key is a one-mana artifact that untaps a creature or artifact at the start of your upkeep — cheap to cast, but the payoff only matters if you're already abusing tap abilities. In a vacuum it's a blank; in the right shell, it's a free activation every turn for essentially nothing.
Format Analysis
Where it lives, where it can’t
| Format | Verdict |
|---|---|
| commander | legal |
| legacy | legal |
| modern | not legal |
| pioneer | not legal |
| standard | not legal |
| vintage | legal |
| pauper | not legal |
| oathbreaker | legal |
Mystery Key sees almost no play outside Commander, and even there it's a niche include rather than a staple. In Commander, the card earns its slot in tap-synergy decks — Urza, Lord High Artificer, Inspired-trigger builds, or any commander that turns repeated tapping into a resource engine. Legacy and Vintage are legal but have no realistic interest; the effect is too slow and too narrow for those formats. The card's ceiling is entirely dependent on the commander it sits behind.
Key Combos
Combo lines featuring this card
Price Context
Current price
$0.08 bulk tier
At $0.08, Mystery Key is deep bulk — a card you pick up as a throw-in or pull from a common box without a second thought. Don't expect that to change; the demand ceiling is narrow enough that no reprint or sudden breakout is likely to move the needle.
Explore
Sources
Mentioned
Updated . Data from Scryfall, EDHREC, and Commander Spellbook.