Single-player games like Theseus Protocol
Below are 9 single-player Steam games similar to Theseus Protocol, ranked by player overlap. Every pick carries Steam's Single-player category, so multiplayer-only titles or always-online games don't sneak in. imho.run pulls the category data from Steam directly — Single-player here matches what the store labels.
Want the full alternatives list (paid + free + Steam Deck + cheaper picks)? See the parent games like Theseus Protocol page.
Ranked picks
- 1
Zero Division
Single-player alternative to Theseus Protocol — playable solo, no multiplayer required.
A roguelite deckbuilder crossed with a CCG, set in a dark cyberpunk world. You will lead a three-man squad against competing factions fighting among the ashes of a world-wide war. Each operator comes with a unique deck that can be customized and augmented.
- 2
DungeonTop
Single-player alternative to Theseus Protocol — playable solo, no multiplayer required.
A rogue-like deck-building experience coupled with table top battles. Choose a hero and allegiance then dive deep into the dungeon, evolving your deck for survival. Each choice you make matters, even in between battles!
- 3
Nowhere Prophet
Single-player alternative to Theseus Protocol — playable solo, no multiplayer required.
Prepare your decks and go on a pilgrimage through the wasteland! Nowhere Prophet is a unique single-player card game. Travel across randomly generated maps and lead your followers in deep tactical combat. Discover new cards and build your deck as you explore this strange, broken world.
- 4
Monster Train
Single-player alternative to Theseus Protocol — playable solo, no multiplayer required.
Monster Train is a strategic roguelike deck building game with a twist. Set on a train to hell, you’ll use tactical decision making to defend multiple vertical battlegrounds. With real time competitive multiplayer and endless replayability, Monster Train is always on time.
- 5
Black Book
Single-player alternative to Theseus Protocol — playable solo, no multiplayer required.
“Black Book” is a dark RPG Adventure, based on Slavic myths, in which you play as a young sorceress. Fight evil forces in card-based battles and explore the world, where humans live alongside mythological creatures.
- 6
Breach Wanderers
Single-player alternative to Theseus Protocol — playable solo, no multiplayer required.
A fresh take on Roguelike Deckbuilders that lets you fine-tune your decks before each run to adapt your strategy on your way to victory. Over 1,200 cards to choose from, ten characters with their own set of unique skills, and dozens of items and missions to evolve your tactics.
- 7
DIMENSION REIGN - ROGUELIKE DECKBUILDER
Single-player alternative to Theseus Protocol — playable solo, no multiplayer required.
Dimension Reign is a roguelike deckbuilder where players control two characters at once to defeat hordes of enemies in an ever-changing landscape. Draw your abilities from your deck, and chain multiple breaks together to decimate entire screens of enemies before they can even get in a hit.
- 8
Astrea: Six-Sided Oracles
Single-player alternative to Theseus Protocol — playable solo, no multiplayer required.
Astrea is a DICE-deck-building roguelike that flips the script on deckbuilders by using dice instead of cards and a unique dual “damage” system: Purification vs Corruption. Build a dice pool strong enough to purify Astrea's out-of-control corruption and save the Star System.
- 9
Slay the Spire
Single-player alternative to Theseus Protocol — playable solo, no multiplayer required.
We fused card games and roguelikes together to make the best single player deckbuilder we could. Craft a unique deck, encounter bizarre creatures, discover relics of immense power, and Slay the Spire!