Though it doesn't have a keyword Joust is one of the most complicated automated interactions in Hearthstone. Understanding exactly how it works and in what situations you'll be favored is extremely important. As such, we've released a new guide to help you get a grasp on what many view as one of the trickier mechanics in the game.

Here's an excerpt from the introduction:
Jousting is a mechanic in which each player reveals a random minion in their decks, compares the mana cost, and declares a winner. There are currently eight cards in the game that use this ability, each of which rewards the player who summoned them for winning said Joust. The player with the higher cost minion is the victor with ties causing the initiator to fail activation. Once completed, the two revealed cards are shuffled back into the deck. It's commonly accepted that this changes its original position in the order.

Joust is a weird mechanic in that it doesn't have it's own keyword. Each and every card reads, "Reveal a minion in each deck. If yours costs more, [do X]." Blizzard has said this is the case because it's more complicated than most other keywords.

Introduced with The Grand Tournament expansion, the Hearthstone team knew they couldn't do a themed content release like this without the age-old ceremony of Jousting.
Originally posted by Blizzard (View Original)Collapse

There are many ways for a knight to prove their valor, but there’s only one true test of mounted might! An aspiring champion may face off against raging beasts in the arena or best skilled challengers in melee combat, but nothing shows off one’s heroic grandeur like mounting a noble steed and charging with a leveled lance in the ultimate chivalrous contest: the joust!