Hidden Volcano

Type: Land — Cave
Set: The Lost Caverns of Ixalan #277 (common)
Price: $0.23 USD

This land enters tapped.
{T}: Add {R}.
{4}{R}, {T}, Sacrifice this land: Discover 4. Activate only as a sorcery. (Exile cards from the top of your library until you exile a nonland card with mana value 4 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Hidden Volcano has 2 printings, first in The Lost Caverns of Ixalan (2023). EDHREC ranks it #4,059 among Commander cards. It appears most in Zada, Hedron Grinder decks (1,451 on EDHREC). 1 public deck on TCG runs it. It has 9 official rulings.

Legality

commander: legal
legacy: legal
vintage: legal
pauper: legal
modern: legal
pioneer: legal
standard: legal
brawl: legal

Public decks that run Hidden Volcano

Goblin Storm Secret Lair Commander, led by Zada, Hedron Grinder

Commanders that run Hidden Volcano most

Deck counts from EDHREC.

Often played with Hidden Volcano

Cards that show up in the same decks on EDHREC.

Rulings

2023-11-10: The mana value of a split card is determined by the combined mana cost of its two halves. If discover allows you to cast a split card, you may cast either half (as long as its mana value is less than or equal to the effect's discover value) but not both halves.
2023-11-10: A spell's mana value is determined only by its mana cost. Ignore any alternative costs, additional costs, cost increases, or cost reductions.
2023-11-10: If you cast a spell "without paying its mana cost", you can't choose to cast it for any alternative costs. You can, however, pay additional costs. If the spell has any mandatory additional costs, you must pay those to cast it.
2023-11-10: When you discover, you must exile cards. The only optional part of the ability is whether you cast the exiled card or put it into your hand.
2023-11-10: If you discover an adventurer card, split card, or modal double-faced card, you might be able to cast that card with either set of characteristics depending on the effect's discover value. For example, if you discover 4 and reveal Galvanic Giant (an adventurer card from Wilds of Eldraine with a mana value of 4), you could cast Galvanic Giant, but not Storm Reading (its Adventure, which has a mana value of 7). If you discover 7 and reveal Galvanic Giant, you could cast either Galvanic Giant or Storm Reading.
2023-11-10: If the discovered card has {X} in its mana cost, you must choose 0 as the value of X when casting it without paying its mana cost.
2023-11-10: You exile the cards face up. All players will be able to see them.
2023-11-10: If you can't cast the discovered card (perhaps because there are no legal targets for the spell), you'll put it into your hand.
2023-11-10: Some spells and abilities that cause you to discover may require targets. If each target chosen is an illegal target as that spell or ability tries to resolve, it won't resolve and you won't discover.