Heroes

Heroes are the stars of your army. You can access them without any randomness: they wait to be summoned in your command zone; you don’t have to draw them from your deck.

Heroes arrive at level 1, and you can spend gold to level them up, even multiple times in a turn. As they level up, they get better stats and new powers (and keep their old powers too). Heroes each have a “spec”. For example, Jaina’s spec is Fire. That means only Jaina can cast “Fire spells.” When heroes reach their max level AND if you didn’t just summon them, they can cast their ultimate spell. Beware of letting your opponent cast ultimate spells—they are really powerful!

Heroes are also great in combat. When a hero levels up from its lowest to middle rank, and when it levels from its middle to last rank, all damage on it is healed. So it can get in an early scuffle and still be fine later.

Killing enemy heroes is so important that you get a bounty for doing so. If you kill an enemy hero on your own turn, all your own heroes (that are in play) level up TWICE for free!

Heroes are fun and flavorful and give the game a ton of character. From a game mechanics perspective, they’re really important because they force you to have your vulnerabilities (in this case, your ability to cast certain spells) on the table where the opponent can interact with them.

Tech Buildings

You start the game with some weak units in your deck that you can summon from your base. If you want more powerful units though, you’ll need to build your tech I building. If you have a tech I building, you can then build your tech II building. That then lets you build your tech III building, which can then produce absurdly powerful, game-winning units.

You have access to three different specs during a game of Codex. For example, an all-red deck would have access to the Anarchy, Blood, and Fire specs. Your tech I building lets you build units from any of those specs. In other words, a tech I building lets you play any card with a bronze bottom on it, regardless of the spec.