One Turn Kill Guide: Core Rules and Deck Builds

One Turn Kill is a PvE deck-building game where card costs equal cards drawn from your deck, requiring players to defeat opponents within a single turn. Success relies on balancing high-draw actions with card recycling before running out of draws.

The title was developed by DenDen and published by Waku Waku Games on the Steam store page. As stated on the Steam community hub, combat focuses on resolving each encounter immediately:

If you cannot defeat the enemy on the first turn, the enemy's counterattack will soon determine who wins. — the Steam store page

How Do Card Costs and Turns Work?

Card cost in One Turn Kill is the number of cards drawn directly from your deck when an action is played. A card with a cost of three immediately pulls three cards from your draw pile into your hand. Because card usage consumes cards from the deck, running out of cards in your draw pile prevents you from playing any further cards that require draws. Pressing the turn end button terminates the encounter and results in defeat.

Managing your deck size requires balancing high-cost actions with cards that recycle cards back into the draw pile:

1. Transcode draws four cards while returning three selected cards from hand to deck.
2. Against the Grain deals damage and returns three cards from hand to deck at the cost of one card draw.
3. Tea Ceremony reduces the cost of two cards with costs of three or less to zero, allowing plays without pulling from the deck.
4. Oxalis's Prayer decreases the cost of all cards in hand by one while requiring one card discard.

Generating unplayable cards such as Overload through Heat Burn provides raw fodder to discard or shuffle back into the deck, preventing card exhaustion during long play chains.

How Do You Structure a 20-Card Deck?

A mission deck is a 20-card setup containing up to three copies of any single card. Effective deck building requires balancing offensive finishers, cost reduction tools, and draw stabilizers. Placing too many zero-cost cards in your deck leaves you unable to draw remaining combo pieces, while stocking too many high-cost cards empties your deck before lethal damage lands.

Core Combat Archetypes and Card Choices

Deck archetypes are specialized 20-card synergies focused on discard triggers, cost manipulation, or infinite recursion.

The discard setup centers around Ferocious Claw and Kunai Throw. Ferocious Claw deals 24 damage for three card draws and discards a card from hand. Kunai Throw deals damage equal to its attack value whenever discarded. Players combine these with Genetic Mutation to add extra Ferocious Claws to the deck, while Iron Coin generates additional discard fodder.

The hand-cost scaling build relies on Heavy Blow. Heavy Blow increases its attack power based on the total cost of cards remaining in hand. Playing Aggra-Ray increases the cost of all cards in hand by one, drastically increasing Heavy Blow's damage. Players then cast Tea Ceremony to drop Heavy Blow's play cost back to zero before attacking.

The infinite loop strategy utilizes Axim Core. Axim Core costs 20 card draws by default, but each card played reduces its cost by one. When cast, it returns to the deck and duplicates four random cards into hand. When paired with Homeward Bound or backdoor, players continuously duplicate Axim Core, Procyon Device, and Tea Ceremony, dealing passive damage with Procyon Device whenever cards are played.

How Do Boss Mechanics Function Across Difficulty Levels?

Boss encounters are sequential combat trials where bosses gain unique passive counters and increased health pools as Bias difficulty rises.

• Captain: Applies Fragile to all cards in hand every two turns. Fragile cards break upon playing another card unless cleared with All-In or returned to the deck with Transcode.
• Azwen: Shuffles Overload cards into your deck every three cards played, while forcing binary choices that either destroy cards in hand or heal her.
• D-rex: Moves along a physical turn gauge toward your position. Players must deal sustained damage to push D-rex back before its timer reaches zero and triggers an instant loss.
• Pastor: Offers three blessings that escalate each phase, such as restoring 99 HP per card played or darkening user interface elements.
• Bulk: Inflicts five Seals onto cards in hand. Sealed cards become locked for five card plays unless played immediately or shuffled back into the draw pile.
• Rita: Alters deck costs after taking damage, shifting between increasing costs, decreasing costs, or applying Fragile to random cards.

Upgrades and Facility Progression

Upgrade facilities are camp stations unlocked through progression where players spend collected upgrade chips to enhance card values. Cards can be toggled freely between their base and upgraded plus versions in the deck menu.

Upgrading Tea Ceremony allows it to reduce any two cards to zero cost regardless of their initial price. Upgrading Kunai Throw adds four attack to the card whenever any other card is discarded. Upgrading Oxalis's Prayer decreases all hand costs by three rather than one. Choosing which cards to upgrade depends on your core damage engine, as over-discounting cards can disrupt the draw rhythm required to dig through your deck.