Caesar III: 3 Open Source Clones Compared
Augustus is a fork of Julius — itself a faithful reimplementation of Caesar III's original engine and logic — that adds new gameplay such as roadblocks, market special orders, a global labour pool, partial warehouse storage, and higher game limits, which is why Augustus save files no longer load in Julius or the original game (though Augustus can still load saves from both). Julius deliberately keeps the original's gameplay bugs intact specifically to preserve save compatibility. CaesarIA is a separate, structurally different project: development halted years ago, and it runs on its own SDL2-based engine rather than being related to Julius or Augustus, requiring a separate copy of Caesar III's graphics, video, and audio files to be placed into its own resource folders.
Comparison table
Availability
- Status
- Playable
- Platforms
- Windows, Linux, OSX, PSVita, Android, Switch, Web
- Play in browser
- YesPlay in Browser
- Mobile
- Android
Project health
- Development status
- Active
- Last updated
- 3d ago
- Stars
- 3,375
- Contributors
- 59
- License
- AGPL-3.0
- Engine
- —
Compatibility
- Requires original assets
- YesRequires original Caesar 3 files from GOG, Steam, or original CD-ROM.
- Modding support
- —
Availability
- Status
- Playable
- Platforms
- Web
- Play in browser
- YesPlay in Browser
- Mobile
- No
Project health
- Development status
- Active
- Last updated
- 2d ago
- Stars
- 2,082
- Contributors
- 117
- License
- AGPL-3.0
- Engine
- —
Compatibility
- Requires original assets
- YesRequires Caesar 3 assets; must have valid Caesar 3 installation folder or copy game files.
- Modding support
- YesCommunity can create and share custom maps, campaigns, and scenarios on the heavengames repository.
Availability
- Status
- Playable
- Platforms
- Linux, OSX, Windows
- Play in browser
- No
- Mobile
- No
Project health
- Development status
- Halted
- Last updated
- 9y ago
- Stars
- 296
- Contributors
- 47
- License
- —
- Engine
- SDL2
Compatibility
- Requires original assets
- YesRequires resources from the original Caesar III game (copy .sg2 and .555 files to resources/gfx folder).
- Modding support
- —
| Title | Julius | Augustus | CaesarIA |
|---|---|---|---|
| Status | Playable | Playable | Playable |
| Platforms | Windows, Linux, OSX, PSVita, Android, Switch, Web | Web | Linux, OSX, Windows |
| Play in browser | YesPlay in Browser | YesPlay in Browser | No |
| Mobile | Android | No | No |
| Project health | |||
| Development status | Active | Active | Halted |
| Last updated | 3d ago | 2d ago | 9y ago |
| Stars | 3,375 | 2,082 | 296 |
| Contributors | 59 | 117 | 47 |
| License | AGPL-3.0 | AGPL-3.0 | — |
| Engine | — | — | SDL2 |
| Compatibility | |||
| Requires original assets | YesRequires original Caesar 3 files from GOG, Steam, or original CD-ROM. | YesRequires Caesar 3 assets; must have valid Caesar 3 installation folder or copy game files. | YesRequires resources from the original Caesar III game (copy .sg2 and .555 files to resources/gfx folder). |
| Modding support | — | YesCommunity can create and share custom maps, campaigns, and scenarios on the heavengames repository. | — |
| Preview | | |
Known limitations
- compatibility: Augustus save files are not compatible with Caesar 3 or Julius.
Frequently asked questions
Are the Caesar III clones on this page open source?
Yes — every clone catalogued here is an open-source project. Availability, license, and development-status details for each one are listed in the comparison table above.
What license do these Caesar III clones use?
Julius and Augustus (AGPL-3.0).
Do I need to own the original Caesar III to play these clones?
Julius, Augustus, and CaesarIA require original game assets to play.
Can I play any of these Caesar III clones directly in a browser?
Yes — Julius and Augustus have a browser-playable build linked in the comparison table above, no install required.
Which Caesar III clone is the most actively maintained?
Julius and Augustus are currently under active development, based on recent commit activity. See the "Development status" row above for every clone's current status.
See the full write-up for each clone, or go back to Caesar III.