Units, events, doctrines
Deploy armies, play one-shot events, forge doctrines that change how your leader fights, and keep your resources for the turn that decides the battle.
A strategy card game
Five nations.
One world at war.
Command the armies of America, Russia, Germany, Japan and France. Build your deck around a legendary leader, conquer the world campaign, then face real players online.
- 5nations
- 15leaders
- 164cards
- 25territories to conquer
Checking the war room…
Free to play · no ads · no purchasesRuns in your browser, on phone and desktop
Choose your side
Five nations, five ways to win
Every nation plays differently. Pick the one that fits your style, then choose among three leaders, each with their own power and their own legendary card.
Signature
How it plays
Easy to learn. Hard to master.
Play units, events, doctrines and traps on a front line. Break the enemy leader before they break yours.
Hidden traps
Set up to three face-down traps. Your opponent only learns what they were when they spring. Bluff, bait and punish.
Leader powers
Fifteen leaders, each with a unique power and a legendary card. Your choice shapes your whole deck and your whole game.
Solo
Conquer the world, one front at a time
Each nation has its own campaign: five territories of rising difficulty, a spoken briefing before every battle, and a special rule that changes the fight. Win, and a new card joins your library.
- 25 territories across 5 campaigns
- 34 reward cards to unlock, including a legendary at the end of every campaign
- Four levels of AI, from Cadet to Emperor
Multiplayer
Duel real players, climb the ladder
Create a free account, then play ranked matches against opponents of similar strength, or invite a friend with a room code. Your rating moves after every game and the best players earn their place on the ladder.
- Ranked matchmaking with a rating system
- Friendly games and private rooms, no account needed
- Build and share your own 30-card decks
Get the game
Play anywhere you like
The same game, the same account, everywhere.
In your browser
No download, no install. Works on computer, tablet and phone (hold your phone sideways). Add it to your home screen to play like an app.
Play nowFree · no account needed to startOn Mac
The native app for Apple Silicon Macs (M1 and later): full-screen, fast and offline for solo play and campaigns.
Download for MacmacOS · Apple SiliconInstalling an unsigned app
This build is not yet signed by Apple, so macOS asks for confirmation the first time. Open the downloaded file, drag Casus Belli to Applications, then right-click it → Open → Open. Or, in Terminal:
xattr -cr "/Applications/Casus Belli.app"Looking for Windows, iPhone or Android apps? The browser version already runs on all of them. Native stores come later.
Questions
Before you march
Is Casus Belli free?
Yes. Playing in your browser or on Mac is free, with no ads and no in-game purchases.
Do I need an account?
No. You can play solo, the campaigns and friendly games with a friend (room code) without any account. An account is only needed for ranked games and the ladder.
Which devices are supported?
Any modern browser on computer, tablet or phone (best in landscape). A native app is available for Apple Silicon Macs.
Is the game historically accurate?
It is a card game inspired by history, not a simulation. Leaders and events are used with respect and a serious tone, and the game contains no hate symbols.
What do you do with my email?
It is only used to confirm your account and to reset your password. It is never shown to other players and never sold. You can delete your account at any time from your profile.
I found a bug or I have an idea.
Write to hello@casusbelli.games. Every message is read.