1. Objective
Be the last player able to provide the required Animal as a new Challenger or Defender when the rules call for one.
What you need
- 2 or more players.
- Casual/open-play deck: 20 or more cards.
- Championship deck: exactly 60 cards.
- No more than four copies of the same common name and collector number; alternate-art, foil, promotional, and First Edition versions count together.
2. The five battle statistics
| Statistic | Winning value |
|---|
| Weight | Higher wins |
| Speed | Higher wins |
| Lifespan | Higher wins |
| Population | Lower wins |
| Length | Higher wins |
Maximum Depth is educational species information and is not a battle statistic.
3. Setup
- Shuffle each legal deck and draw six cards.
- Choose the first player by any fair method.
- Reveal the starting Challenger first.
- Reveal the starting Defender second.
- Each player fills their Pool with up to five Animals.
The first player skips the first-turn draw but still attacks.
4. Turn sequence
- Draw: draw one card, except the first player on the first turn.
- Pool Phase: place all desired Animal Cards into your Pool, up to five.
- Establish Challenger and Defender: the Challenger is known first, then the opponent selects the Defender.
- Attack: choose one unused battle statistic and compare the official printed values.
- Resolve: follow the challenge and Defense Chain result.
- End Phase: only the player whose turn is ending refills their hand to three cards if below three. There is no maximum hand size.
5. Defense Chain
If the Challenger defeats the active Defender, that Defender is discarded. The defending player may promote a replacement Animal that was already in their Pool. A different unused statistic is selected for the next comparison.
- Cards from hand cannot enter an active Defense Chain.
- Each of the five battle statistics may be selected only once during the same attack sequence.
- If a replacement Defender wins, both active Animals are discarded and control changes to the defending player.
- If all five statistics have been used and the attack has not ended, the Challenger is discarded and the surviving Defender becomes the next Challenger.
6. Important gameplay reminders
- Once an Animal becomes the Challenger, it cannot be voluntarily replaced.
- A player with an active Challenger must attack unless a card effect specifically allows otherwise.
- Whenever control of the Challenger changes, the current attack ends and a fresh turn begins.
- More specific card text overrides a general rule.