Jev beat Slay the Spire 2.
On Ascension 0. Still counts.
182 runs, a lot of changes, and one winning Ironclad deck. Here’s the climb.
Jev is an AI model from TypeSafe. It chose the moves in these runs.
How far we got
Each bar shows where one run ended. Select a bar or use the slider.
What we asked Jev
We gave Jev the visible game state and a set of legal moves. It answered seven questions about those options, then reviewed its choices before acting.
Loading recorded answers…
Questions shortened for readability. Answers from the winning run’s logs. These are choices returned by Jev, not a transcript of its internal reasoning.
Inside the winning fight
Watch Jev choose, play one action, then check the game again.
At 0 energy, Jev found two more attacks. It started the next turn at 3 HP—and finished the boss.
Loading recorded decisions…
Visible effects
49 recorded decisions across nine turns, including card selections. The runner executes only the first action in a chosen sequence, then asks Jev again.
How we ran it
- The game
- Ironclad, Ascension 0, standard runs. No custom seeds or gameplay-changing mods. STS2MCP let the runner read the game and send actions. We added an exclusion for Sword in Stone.
- What Jev could see
- Cards, enemy intents, displayed rules, the current deck and recent observations. No future draw order, hidden enemy behavior or named boss guides.
- Who chose the moves
- Code listed legal actions and short card sequences, with estimates for effects it could calculate. Jev chose an option. The runner played one action, read the game again and asked Jev for the next choice.
- What we changed
- We edited the code between runs and sometimes during them, and recovered paused or stalled sessions. The timeline records the changes. Jev was not training itself on the losses.
- The experiments
- Most tests used saved game states without playing the game. In one live run, Luna reviewed two choices before Jev made the final call. We stopped that trial because it was slow. The winning run used Jev alone.
- How we counted
- Wins and losses came from the game’s saved history. Token usage came from Jev’s decision logs. Costs use the published API price; interrupted requests can leave gaps in the logs.
What it cost
Estimated cost across all 182 runs, in USD.
| Run | Act · Floor | Input tokens | Output tokens | Total tokens | Est. cost |
|---|
Calculated from logged usage at $0.042 per million input tokens. Output is free. TypeSafe pricing, checked September 23, 2026. Offline tests and Luna costs are excluded; interrupted requests may be missing. Your bill may differ.
What we changed
Changes used in real runs, plus tests on saved game states.
The first win
On run #182, Jev defeated Aeonglass, collected rewards at 9 HP, and completed The Architect ending. The game’s saved history confirms the victory.
The winning build
A 46-card deck with 18 relics. Nutritious Soup made all five Strikes free; Brimstone, Inflame+ and Red Skull supplied Strength. Vulnerable and multi-hit attacks added damage, while Unmovable+, Rage and defensive relics supported survival. Lord’s Parasol supplied a large haul of cards and relics from merchants in Act 3.
Full deck and relics
Deck · 46 cards
- Aggression×1
- Armaments×3
- Ashen Strike×1
- Bash×1
- Battle Trance+×1
- Bully×1
- Catastrophe×1
- Conflagration×1
- Dark Shackles×1
- Defend×2
- Demon Form×1
- Dismantle×2
- Fiend Fire×1
- Havoc×1
- Headbutt×1
- Hemokinesis×1
- Inflame+×1
- Iron Wave×2
- Juggernaut+×1
- Molten Fist+×1
- Perfected Strike×1
- Pommel Strike×3
- Rage×1
- Rampage×1
- Salvo×1
- Secret Technique×1
- Shrug It Off×2
- Spite×1
- Stone Armor×1
- Strike×5
- Twin Strike×1
- Unmovable+×2
- Uppercut×1
“+” marks a permanent upgrade. All five Strikes had Tezcatara’s Ember: 0 energy, +3 damage and Eternal. Bash had Sharp 2.
Relics · 18
- Burning Blood
- Stone Humidifier
- Juzu Bracelet
- Sparkling Rouge
- Horn Cleat
- Nutritious Soup
- Anchor
- Venerable Tea Set
- Lord's Parasol
- Red Mask
- Gambling Chip
- Dolly's Mirror
- Potion Belt
- Petrified Toad
- Stone Cracker
- Red Skull
- Brimstone
- Gorget
Final deck and upgrades checked against the winning save; names checked against the final boss log. Temporary combat upgrades are not listed.
About the data
This page covers the 182 completed runs through September 23, 2026. Wins and losses come from the game’s saved history. Floors, decisions and code versions come from the matching Jev logs. The new Ascension 1 run is excluded.
One logged decision can include several Jev calls. Token totals count those calls once, including logged previews and cancelled decisions. A run can span several code versions; dates show the first logged use unless marked otherwise. The chart averages up to ten consecutive runs and groups days by the first decision.
The page contains summarized gameplay data. Raw logs, credentials, account IDs and seeds stay private.