A supplementary booster set is designed specifically to enhance and expand constructed play and is not designed for booster draft play.

Crucible of War introduced six new young heroes:

• Kayo, Berserker Runt, a Brute that packs a punch
• Benji, the Piercing Wind, a nimble Ninja
• Kassai, Cintari Sellsword, a Warrior seeking spoils of war
• Shiyana, Diamond Gemini, a diplomatic Shapeshifter
• Data Doll MKII, an artificial Mechnologist
• Kavdaen, Trader of Skins, a Merchant where no deal is off the table

The Crucible of War booster set contains a total of 198 cards, with the following configuration and estimated rarity breakdown:

• 1 Fabled (1 per ??? packs)
• 2 Legendary (1 per 240 packs)
• 36 Majestic (1 per 4 packs)
• 56 Rare (1.75 per pack)
• 103 Common (7 per pack)
• Premium Foil (1 per pack, with First Edition containing 1 Cold Foil every 22 packs)