Reading Cards

Top left number: A card's mana cost. You need to pay the amount to play the card, and if you don't have enough you can't play it.
Bottom left and right: A unit's ATK (ATtacK) and HP (Health Points). ATK signifies the amount of damage the unit does in combat, while HP is the amount of damage required to defeat it.
Top text: A card's name. The small text higher up is the name of the artist whose art was used.
Bottom text: The text right underneath the art is the unit's description, which affects how the card behaves. This description often uses keywords, the meaning of which will be explained later. There is also smaller text under the main description that explains what kind of card the card is.

Gameplay

The two players alternate turns until one of the players wins or concedes. The player who has more cards in their deck has the first turn. If both players have the same amount of cards, throw a coin. The first player starts with 4 cards drawn and 5 mana, while the second starts with 5 cards and 6 mana.

Each player can take up to 3 actions per turn, after which their turn ends and the opponent's begins. The goal of the game is to either make 3 sacrifices or to destroy the enemy obelisk.

Possible actions are as follows:

Deckbuilding

There aren't a lot of limits while building your deck, but keep the following rules in mind:

After building your deck, pick out any 6 cards from it - they will be in your library. The rest will be your main deck.

Keywords

Frontline: When a frontline unit can be attacked, only frontline units can be attacked. Only applies to attacks with units, and is ignored by allies and units who have Ranged.

Tough: When this unit receives damage and has more than 1 remaining HP, this damage can only reduce its remaining HP to 1.

Counter-attack: After being attacked, if possible, this unit will automatically attack the attacker. This exhausts the unit as normal, and happens right after the attack. Can not counter-attack if attacker has Ranged, unless this unit also has Ranged.

Thorns: When attacked, attacker receives damage equal to damage dealt. Ignored if attacker has ranged, unless the target also has ranged.

Armor X: Decreases all instances of damage received by the armor value (the X), but damage can never be decreased below 1 by this keyword.

Draining: Creatures attacked by this unit will exhaust. Takes priority over Counter-attack.

Ranged: Ignore attack target Frontline, Counter-attack and Thorns. Counter-attack and Thorns will not be ignored if target also has Ranged.

Vampirism: This unit heals for amount of damage it deals whenever it attacks.

Immortal: This unit is transferred back to the owner's hand instead of the discard when defeated.

Rush: You can command this unit immediately after playing it, without using up an action.

Swift: Indicates that an action that is normally supposed to use up a turn action does not use it up. So for example "Attacking is swift" in a creature's description would mean that commanding it to attack does not consume an action.

Triggers

Kill: [effect] - The effect happens whenever this unit defeats another unit.

Defeat: [effect] - The effect happens when this unit is defeated.

Exhausted: [effect] - The effect happens when this unit is exhausted.

Played: [effect] - The effect happens when this card is played.

"⤥: [Effect]" OR "X✧: [Effect]" - Manual trigger. You can command the unit to execute the effect instead of attacking/moving. "⤥" means "Exhaust" and "X✧" means "pay X✧". If both are present, you need to do both.

Some manual triggers literally have "X✧" as their cost. You can pay any amount of✧to activate such a trigger, and the effect will be adjusted depending on the amount.

Etc. And Rulings

Formats

Standard

Default rules. Both of the players' obelisks are located in the center battlefield. Each player also has 1 pylon summoned by default - in the opposite edge battlefields.