Magic's Lost Caverns of Ixalan set is a return to the dinosaur-hunted jungles of Ixalan, but it's also a return to a theme Magic has tinkered with before: the world underground. As head designer Mark Rosewater mentioned in his Making Magic column, the dungeon cards from Adventures in the Forgotten Realms presented one angle on underground exploration in card form, but The Lost Caverns of Ixalan tackles another, one with more of a focus on "resource acquisition and the building/upgrading of items." To say the quiet part out loud: it's loosely inspired by Minecraft.
That means there's a Diamond Pick-Axe card, and a new ability called Craft, which lets you transform artifacts into more powerful cards. There's no "Mine" mechanic but there is Descend, which triggers various effects when you discard to the graveyard, and Discover, which lets you flip cards from your deck into exile until you find something with a set mana value that you then either cast or put into your hand. The Explore mechanic from the original Ixalan set returns too, letting you draw a card and if it's a land play it immediately, which is nicely thematic.
