Each run starts with a basic deck of strikes and defends, three energy per turn, and a branching map stretching three acts to the final boss. Play cards to deal damage or gain block. Enemies telegraph their next move, turning every turn into a tactical puzzle. Win a fight, pick one of three new cards. Find a relic that changes how your entire deck works -- suddenly that useless skill card becomes the centerpiece of a broken combo. The energy system forces hard choices: you can see the perfect play but you only have three energy to spend. That tension is the game.

Summer Engine helps you build this system through conversation. Describe your character classes, your card pools, your relic effects. The AI sets up the combat loop, the map generator, and the reward pipeline while you focus on what makes your game different: the cards only your game has, the relics that create strategies nobody expects, the enemies that punish lazy play.

Slay the Spire defined the modern deckbuilder by proving that a tight combat loop, meaningful deck-thinning decisions, and relic synergies create near-infinite replayability. Every run feels different because every combination of cards and relics opens new strategies. That depth is what you are building toward.

• Solo devs who want the Slay the Spire combat loop without building the card engine from scratch.
• Designers with a unique character class concept and a notebook full of card ideas ready to playtest.
• Anyone inspired by Slay the Spire, Monster Train, or Griftlands who wants to build their own take on turn-based card combat.
• Small teams building a vertical slice for Steam Early Access or a publisher pitch.

• Character Class Prototyping

  Get a working combat system fast so you can iterate on what matters: unique card pools, class mechanics, and the synergies that make each character feel distinct.

• Three-Act Vertical Slice

  Build a complete run from floor one to the Act 3 boss. Branching maps, elite encounters, shops, rest sites, and enough relics to make each playthrough feel different.

• Early Access Foundation

  Create a solid base with one character, 70+ cards, 20+ relics, and three acts. Ship it, get feedback, add characters and content based on what players want.