Bug fixes
Fixed some UI bugs, and billing issues that could affect a player's access to premium features.
Fixed some UI bugs, and billing issues that could affect a player's access to premium features.
Quantum Chess
- Released
- Mar 14, 2025
- Platforms
- WindowsmacOSLinux
- Last updated
Updates & announcements
- Developer postOriginal post
- Developer post
Quantum Chess Remastered 1.0
Quantum Chess hit 1.0 today. The remaster soft-launched in May and has been under continuous development since. Sound, replays, in-game guides, puzzle packs, correspondence, keyboard-only play, a proper mobile pass. And with it, a feature that we've always wanted to create. A way
Original postQuantum Chess hit 1.0 today. The remaster soft-launched in May and has been under continuous development since. Sound, replays, in-game guides, puzzle packs, correspondence, keyboard-only play, a proper mobile pass. And with it, a feature that we've always wanted to create. A way to experiment with different ways to play Quantum Chess... The Alchemy League ships today.
The Alchemy League
A seasonal online ladder where every season changes the rules of quantum chess, without touching the standard game you already know. Fresh rating each season, live or correspondence.
Season 1 removes merge moves and adds a phase dial beside the board. The dial puts a quarter-turn phase rotation on your next move. Phase is invisible on its own, but split a piece back onto one of its own halves and the two halves interfere. In the simplest case, with the interference played right after the split, the dial at rest gives a coin flip, one click lands the piece wholly on one square, and three clicks wholly on the other. That is specific to the most basic state, though. Other moves can change the phase or entanglement between pieces, and mastering the effect means learning to read the phase and entanglement overlays on the board. The dial turns a coin flip into a choice. And with merges gone, a phased split is the only way to make a split piece whole again.
Season 1 runs October 1 to January 1. The queue is open now for unrated games under the season rules, and there's a pass-and-play practice board for learning the dial. Playing rated league games earns the Alchemy board theme when the season ends.
Badges
Play now earns badges you wear beside your name in matches, on the leaderboards, and on your profile. Click any badge anywhere to see it full size and wear it.
- The league ladder: Nigredo for playing, Albedo and Citrinitas for wins. Once the community plays 500 rated league games, everyone who took part earns Prima Materia and eight rank badges go live, from Vitriol at top 100 to Magnum Opus for reaching #1.
- Lifetime tracks: online games from Bell Pair to Einstein-Rosen Bridge at 500, AI games from Turing Test to Maxwell's Demon for beating the Hard AI, and leaderboard positions from Ground State to Quantum Supremacy for #1.
- Feats: quantum moments like Copenhagen, a win by measuring the enemy king out of existence, and Decoherence, the badge of shame for measuring your own king to death. Win streaks earn Coherence, Phase Lock, and Pure State.
Every game you've already played counted. Badges you earned before badges existed are waiting the next time you sign in (if possible).
Achievements
The whole badge set mirrors into Steam achievements.
What your Steam copy includes
Your purchase is the full desktop game, every achievement, friend challenges through Steam's own invite picker, and six months of premium included. Link your Steam account in the game to redeem it.
Premium unlocks:
- Wearing every badge you earn. Free accounts can wear some of them; premium wears them all.
- The full puzzle library: every official pack plus unlimited community puzzles.
- Unlimited correspondence games. The free tier runs one at a time.
- The Hard AI, and uploading an engine of your own to play against.
- Analysis mode with the full quantum state at every ply, and deeper engine evaluation.
- Alchemy League rules after a season ends. Season 1's phase dial stays playable for premium members after January 1.
And the rest of 1.0
- Premoves actually work: they queue, show on the board, and tell you if they became illegal.
- The AI plays on past move 64 and no longer resigns instead of moving in lost positions.
- Online games show both players' real usernames on the nameplates.
- The whole game is playable from the keyboard, and phones got a full usability pass.
- Undo in pass-and-play games, two new puzzle packs, and a long list of fixes to online rooms, draw offers, and correspondence play.
Season 1 starts October 1. Nobody has ever been good at this variant, and for about five more weeks, nobody is. See you on the ladder.
- Developer post
Bug Fixes
Fixed some multiplayer stuff on the back end, and deployed a prototype discord and steam friend challenge capability. Let us know if it doesn't work.
Original postFixed some multiplayer stuff on the back end, and deployed a prototype discord and steam friend challenge capability. Let us know if it doesn't work.
- Developer post
Patch eval bar
Fixed a bug that prevented eval bar in local huma vs human games
Original postFixed a bug that prevented eval bar in local huma vs human games
- Developer post
Patch window focus bug
Fixed a bug that occasionally caused the window to lose focus and not accept mouse clicks after re-focus
Original postFixed a bug that occasionally caused the window to lose focus and not accept mouse clicks after re-focus
- Developer post
Network Fix
Fixed a bug that was preventing the steam build from connecting to the back end.
Original postFixed a bug that was preventing the steam build from connecting to the back end.
- Developer post
Soft Launch Quantum Chess Remaster
We've completely rebuilt Quantum Chess from the ground up. New multiplayer back end, new AI, new puzzles, new UI, Discord rich presence support (not fully featured yet). Join us in discord and let us know what needs polish.
Original postWe've completely rebuilt Quantum Chess from the ground up. New multiplayer back end, new AI, new puzzles, new UI, Discord rich presence support (not fully featured yet). Join us in discord and let us know what needs polish.
- Developer post
Quantum Chess Reborn
Hey Steam! We're still here, and we've been plugging away at a behemoth of tech debt. Things need to change to make Quantum Chess viable. The game has been through a lot of iterations and a lot of collaborations over the past decade. It’s become a massive Unity project full of te
Original postHey Steam! We're still here, and we've been plugging away at a behemoth of tech debt. Things need to change to make Quantum Chess viable. The game has been through a lot of iterations and a lot of collaborations over the past decade. It’s become a massive Unity project full of tech debt, and it’s too unwieldy to live up to its potential. So I’m rebuilding it. Again. This time web native, using Quantum Forge. The goal is to solve two problems at once: accessibility and iteration speed. Right now, changes take months and multiple engineers. After the rebuild, I’ll be able to ship features fast, and the game can finally start growing into what it was always meant to be. I wrote a blog post discussing the whole situation, check it out: https://quantumnative.io/blog/qc-history-and-future/.
Rest assured, Steam supporters will be taken care of when the project is done. We'll be publishing a new Steam release based on the new build, with built in Steam and Discord integrations at the very least, and likely some premium features. Follow along at chess.quantumnative.io, and join the Quantum Chess community to help guide this next iteration.
- Developer post
Super Secret AI Update
Super secret PC update with our new AI player finally released. Mac and Linux to follow soon. Shhhh...
Original postSuper secret PC update with our new AI player finally released. Mac and Linux to follow soon. Shhhh...
- Developer post
New Stuff!
Release 1.1.0 New Features - New animations - Post game analysis board for played games - In game analysis for spectated games - Analysis games support forked game histories - Can view board state for previous ply's - Sandbox supports forked game history's - Sandbox can force mea
Original postRelease 1.1.0
New Features
- New animations
- Post game analysis board for played games
- In game analysis for spectated games
- Analysis games support forked game histories
- Can view board state for previous ply's
- Sandbox supports forked game history's
- Sandbox can force measurement outcomes
- Multiplayer "dedicated" games. Dedicated server controls game state.
- Added fen and move copy button to game and sandbox
- Added ability to paste a fen + moves into sandbox
- Local Play, for side by side multiplayer
- New quick start tutorial
- In Sandbox and in Analysis mode, you can force measurement outcomes using the .m0, .m?, and .m1 buttons
- Squashed several bugs and even a few quantum bugs - Sorry! No more duplicating Kings with entangled castling.New Animations
The game now shows "conflict" animations that result in measurements of the game state. We hope this helps players understand when and why measurements occur.
Analyzing Games
After a completed match, you can now analyze the game, and explore different moves!
While spectating you can swap over to analysis mode at any time and explore different measurement outcomes! While analyzing a game, click a previous ply to explore an alternate history from that point.Dedicated Multiplayer
Dedicated games hold and modify the state of the game on a dedicated server, instead of local machines. This sets us up for some other cool features in the future.
Local Play
Side by side let's you play against a friend on the same screen, and lays the groundwork for a re-release of an AI opponent.
We also packed in a lot of bug fixes. When you find more, be sure to let us know in our Discord!
As always, thank you for your continued support.
- Developer post
Update 3/19/2021
Some updates to fix a number of errors and bugs we're seeing in the logs. This should (hopefully) fix the multiplayer desync bug.
Original postSome updates to fix a number of errors and bugs we're seeing in the logs. This should (hopefully) fix the multiplayer desync bug.
- Developer post
Update 2/11/2021
Added Features Asynchronous Multiplayer You can now play in "Correspondence" mode. These games have up to 3-day turn timers, and you can play more than one at a time. Matchmaking There are two separate matchmaking queues. One for real time games, and one for async games. Move Arr
Original postAdded Features
Asynchronous Multiplayer
You can now play in "Correspondence" mode. These games have up to 3-day turn timers, and you can play more than one at a time.
Matchmaking
There are two separate matchmaking queues. One for real time games, and one for async games.
Move Arrows
Shift-click to draw arrows between squares
Visual Updates
Added piece animations
- Developer post
Multiplayer Update
Here is a quick update to add some quality of life improvements for new players. Now, the first time you open the game, the help menu will pop up. It has a handy link, right at the top of the page, to join our Discord community! This is the best place to find other players, and g
Original postHere is a quick update to add some quality of life improvements for new players. Now, the first time you open the game, the help menu will pop up. It has a handy link, right at the top of the page, to join our Discord community! This is the best place to find other players, and get help, right now.
We've also added a couple of multiplayer improvements, with low time warnings, and a more obvious visual and sound effect when it is your turn.
We're working hard to get correspondence games in, and matchmaking. In the mean time, we hope the new additions will make things a little easier.
- Developer post
Prepare to enter the quantum realm
The time has come! Quantum Realm Games has partnered with Arcanforge to bring Quantum Chess to the next level. Here's what is going on. Going Quantum In 2019, we were approached by Google AI Quantum to see if we could run Quantum Chess on their quantum computing hardware. In July
Original post
The time has come! Quantum Realm Games has partnered with Arcanforge to bring Quantum Chess to the next level. Here's what is going on.
Going Quantum
In 2019, we were approached by Google AI Quantum to see if we could run Quantum Chess on their quantum computing hardware. In July of this year, we successfully demonstrated the fruits of that labor at the Google AI Quantum Summer Symposium! Check out the video of our presentation.
Watch on YouTube This success gave us the momentum we needed to push Quantum Chess to reach its potential. We were able to secure generous funding from IQIM, and an amazing development partner, to bring you the next iteration of the game.
New Moves
The old quantum move has seen its last days. We've replaced it with the new split and merge moves!
Splitting the Universe
With the new split move, players have the power to create superposition, where their pieces exist in multiple squares at the same time.
You perform a split move in two steps:
- Select the source square with the piece you want to move.
- Click and hold on the first target, drag to the second target square, and release.
Merging the Universe
With the merge move, players have the power to combine a split piece back together.
You perform a merge move in two steps:
- Click and hold on the first source square, drag to the second source square, and release.
- Select the single target square.
Entanglement and Phase Display
The game has always been built on top of a simulation of a quantum state. But before, we didn't have a great way to show that information. Now we do! If you right-click on a piece in superposition, it will show the relative entanglement and phase display.
Entanglement
The outer ring shows whether other pieces are entangled with the one you selected.
If the rings are the same color, the pieces are entangled to exist on the same board(s).
Phase
The "radar" wedges show the phase rotation of other pieces, relative to the one you selected.
The relative phase can change how pieces interfere with each other, leading to unexpected outcomes.
Sandbox Mode
With sandbox mode, you can drag pieces onto the board and experiment!
You can reach sandbox mode from the side drawer in the main menu.
Multiplayer
Gone are the days of unstable multiplayer connections. We've adopted a completely new networking architecture. It is now easier to get a game going with a friend, or a member of our Discord community, and even to spectate other players.
Tournament
A great way to see multiplayer in action is by watching the first ever Quantum Chess tournament, which was live on Anna Rudolf's twitch stream! We saw some new strategies, and live demonstrations of running on actual quantum computing hardware, and even a cameo from Alex Winter! Check out the vods.
Quarter-finals
Semi-finals
FinalThe Future
So, what's next? A lot. Pushing into the next stage of development, we have a number of features and collaborations on the roadmap.
Game Features
- We're revisiting AI, this time with more brain power and some donated compute resources.
- We're expanding and improving the multiplayer experience with features like chat and match making.
- We're developing a new game mode that involves Quantum Chess puzzles.
- We're working toward a mobile release.
Collaborations
- We're continuing work with Google AI Quantum, to expand the ability to run on quantum computing hardware.
- We're going to be doing more quantum computing workshops with Qubit by Qubit, aimed at high school students.
- We've been contacted by a number of other educational interests, and will be exploring applications of Quantum Chess with them.
- We're looking at other ways to collaborate with Anna Rudolf, and the chess community at large.
Honestly, that is just a taste of what we're looking at going forward. We're very excited to bring this next iteration of Quantum Chess to the world. If you want to keep active with the community, make sure and join our Discord server. There you can leave feedback and bug reports, and find other players to jump in a game with. See you in the quantum realm!
- Developer post
Update: AI and Multiplayer
It has been a little while since the last update so I wanted to give players a quick overview of the work being done. AI is the big thing. We now have a fairly stable AI for the next version. I still wouldn't call it "good", but it isn't "bad" either. It makes some fairly intelli
Original postIt has been a little while since the last update so I wanted to give players a quick overview of the work being done.
AI is the big thing. We now have a fairly stable AI for the next version. I still wouldn't call it "good", but it isn't "bad" either. It makes some fairly intelligent plays and for the most part avoids obvious mistakes. It is also capable of making quantum moves. It is based on a standard chess AI, so players familiar with chess may notice some patterns of play often seen there.
I've also settled on a new networking architecture for multiplayer that should alleviate a lot of the connection headaches and allow for the easy implementation of some nice features like games that persist through different play sessions. I'll keep updating as work here progresses.
Again, thank you to all of the players for your continued support and patience.
- Developer post
Sandbox Mode
Hey everyone, here's another update on progress. I've been hard at work on getting the AI up and running, but debugging was taking a long time. So I took a sidetrack and implemented a long requested feature, sandbox mode. Don't be too hard on the look of the new UI, it is being u
Original postHey everyone, here's another update on progress.
I've been hard at work on getting the AI up and running, but debugging was taking a long time. So I took a sidetrack and implemented a long requested feature, sandbox mode. Don't be too hard on the look of the new UI, it is being updated, but here is a sneak peek at Sandbox Mode functionality!
This mode serves multitple purposes. It will be a great way to explore different dynamics from specific board states. It is also an incredible tool in both debugging (AI and otherwise), and in helping develop the new tutorial. I hope you will all enjoy it!
- Developer post
Phase Indicator
Relative phase is an important concept in quantum physics because it can change the outcome of an operation through interference. In Quantum Chess, moves are unitary operations, and their outcomes can change if the underlying state has certain phase characteristics. Until now the
Original postRelative phase is an important concept in quantum physics because it can change the outcome of an operation through interference. In Quantum Chess, moves are unitary operations, and their outcomes can change if the underlying state has certain phase characteristics.
Until now the player has only been presented with probability information. This could lead to confusing situations where moves appeared to have no effect. After some careful thought, and some math, the game can now display some basic relative phase information. It isn't complete, but it should be relevant to a lot of moves. Here is an example.
The Merge move is designed to undo a Split move. If used immediately after a split it should result in 100% of the piece being in the target square (assuming there are no pieces blocking the paths). Here we can see how it acts on the queen.
Notice the yellow lines on the queens involved in the move are pointing in the same direction. We call this being "in phase".
Now if we perform a Standard move for the queen in d2, moving it to d3, and then perform the Merge move, we get something different.
Notice that the standard move has caused the yellow lines to no longer point in the same direction. The piece that was moved picked up a relative phase of pi/2 compared to the one that didn't move.
Phase can be a complex topic. But if you play around with moves, and take notice of how the phase indicators relate to each other, you can gain an intuition for how it will change the outcomes. This is the first successful attempt at getting meaningful phase information into the game, and it will likely evolve.
I can't wait to get this out there for people to play with!
- Developer post
Split and Merge Moves
Hey everyone, I wanted to show you what the new quantum moves will be like when the next version is released. As stated previously the "double" move will be going away. It will be replaced by two quantum moves. The Split move will allow a piece to split and occupy two different p
Original postHey everyone, I wanted to show you what the new quantum moves will be like when the next version is released. As stated previously the "double" move will be going away. It will be replaced by two quantum moves.
The Split move will allow a piece to split and occupy two different positions. This is similar to the "double" move except there is no possibility that the piece didn't move, and it can only reach one standard move away.
The Merge move is designed to undo a Split. The player will select two squares with the same type of piece, then select a single "target" that is reachable by both.
You can also see the experimental phase indicator in these gifs (more on that later)!
- Developer post
Australian Pricing
It was brought to my attention that Australia was unable to access the game. I've submitted a change that should fix the problem.
Original postIt was brought to my attention that Australia was unable to access the game. I've submitted a change that should fix the problem.
- Developer post
Still Here and Developing. Join Our Discord!
So I have seen an influx of new players and I wanted to let everyone know this is still an ongoing project, and due to some life changes it is getting a lot more love and attention than it has in the past months. Here is where we are at right now. Our most active community member
Original postSo I have seen an influx of new players and I wanted to let everyone know this is still an ongoing project, and due to some life changes it is getting a lot more love and attention than it has in the past months. Here is where we are at right now.
Our most active community members hang out in our discord channel which can be found here
The currently available game features the "double" quantum move, a buggy networked play experience, and an AI that doesn't understand quantum moves. But it is playable and in my opinion quite fun. Some people have no problem establishing networked games, others can't seem to get a stable game going no matter what they try. The best way to get a networked game going is to ask in the discord.
The next version of the game is under heavy development. It will feature a much stronger AI that will be able to make quantum moves. It will also use a different rule set. Instead of the "double" quantum move it will be a "split" move. The piece will always move, and it will split to occupy two different positions that are one classical move away. A new networking infrastructure is being investigated as well.
To keep up with the latest in ongoing development, and add your input as the game evolves, please join the Discord community. I will try and keep updates here a bit more consistently.
Thanks For The Interest And Support!