Caesar 3 on Windows 11, Mac and Android: Julius vs Augustus

Short answer

Julius is a free, open-source re-implementation of Caesar III with the original game logic and save compatibility, plus widescreen and quality-of-life fixes. It runs on Windows, macOS, Linux, Android, Switch, Vita and in browsers. Its fork Augustus adds long-wanted gameplay changes. Both need your own Caesar III files (patched to 1.0.1.0). Latest Julius release: 1.8.0, 31 July 2025.

This site is not affiliated with the Julius or Augustus developers, Impressions Games, Sierra or Activision. We do not host any files and only link the projects’ official pages.

What it is

Caesar III, Impressions Games’ Roman city builder, came out in 1998. The original runs at fixed resolutions and has trouble on current Windows, especially in windowed mode.

Julius is “a fully working open-source version of Caesar 3, with the same logic as the original, but with some UI enhancements, that can be played on multiple platforms” (Julius README). Bianca van Schaik built it by reverse engineering the original. Its goal is “exactly the same game logic as Caesar 3, with the same look and feel”: saves are 100% compatible both ways, and even the original’s gameplay bugs are kept on purpose.

Augustus is a fork of Julius that “intends to incorporate gameplay changes”. The Julius README itself recommends it: “use Julius for a more vanilla experience with some visual improvements, or Augustus for a different gameplay experience.”

Current status

Julius: Working. Latest release 1.8.0, 31 July 2025, with Windows, macOS, Linux (AppImage and Flatpak), Android, Switch, Vita and an Emscripten browser build. The repository was last updated on 12 September 2026.
Augustus: Working and very active (last update 2 November 2026). The last numbered release is 4.0.0 from 28 December 2023; the project now points players to frequent development builds for Windows 64-bit and Flatpak, and offers a browser version.
Android: Julius is on Google Play.

Julius or Augustus?

	Julius	Augustus
Game rules	Identical to Caesar III, bugs included	Changed and extended
Saves	Fully compatible with Caesar III both ways	Loads Caesar III and Julius saves; its saves work only in Augustus
Additions	Widescreen, windowed mode, quality-of-life UI, MP3 music	All of Julius plus roadblocks, market special orders, global labour pool, partial warehouse storage, higher limits, zoom, new scenarios
Pick it if	You want the original game, playable today	You want Caesar III with modern city-builder conveniences

What you need

Caesar III from your own copy: GOG, Steam or the original CD-ROM.
Version 1.0.1.0 of the game. If Julius says it is missing, the patches page has the update.
Write access to the game folder, because saves are stored there.
Optional: the high-quality MP3 soundtrack Sierra once offered; Julius and Augustus both support it.

We do not link any copies of the game files.

How setup works (overview)

Install Caesar III from GOG, Steam or CD.
Download Julius from its releases page (or Augustus from its README’s download table).
Either copy the program into the Caesar III folder, or run it from its own folder and point it at the Caesar III folder when asked.
Choose a resolution in the options and play your campaigns; old Caesar III saves load directly in Julius.

On Android, install the APK or the Google Play app and copy the Caesar III folder to the device when prompted.

Common problems

“Missing update” message: patch the game to 1.0.1.0 using the link above.
Cannot save: the game folder is read-only (often under Program Files). Run Julius from a writable copy of the folder.
Augustus save will not open in Julius: expected; Augustus saves are one-way.
A bug from the original game appears in Julius: intentional, to keep saves compatible. The wiki lists known Caesar III bugs and idiosyncrasies.

FAQ

How do I play Caesar 3 on Windows 10 or 11?

Use Julius or Augustus, two free re-implementations that run natively on modern Windows, macOS and Linux with widescreen support. Both need the files from your own Caesar III, such as the GOG or Steam release, patched to version 1.0.1.0.

What is the difference between Julius and Augustus?

Julius copies the original game's logic exactly, bugs included, so saves are fully compatible with Caesar III in both directions. Augustus is a fork that changes gameplay, adding roadblocks, market special orders, a global labour pool, partial warehouse storage, bigger limits and zoom. It loads Caesar III saves, but its own saves only work in Augustus.

Can I play Caesar 3 on Android?

Yes. Julius has an Android APK on its releases page and an app on Google Play, and Augustus has its own APK. You copy your Caesar III files to the device.

Can I play Caesar 3 in a browser?

Julius releases include an Emscripten build for browsers, and the Augustus project hosts a browser version. Both still ask you for a Caesar III installation folder; neither includes the game.

Do I need the 1.0.1.0 patch?

Yes. Both READMEs say your game must be patched to 1.0.1.0. Digital releases are usually already patched; if Julius says the update is missing, its wiki links the patch.

Unofficial. This page is written by an independent directory. It is not made by, endorsed by or affiliated with Sierra Entertainment (developed by Impressions Games) or Bianca van Schaik (Julius); Keriew and contributors (Augustus) (Julius and Augustus (Caesar III re-implementations)'s author). We do not host any files, and we never link to game files, ROMs or ISOs.

Sources

This page was last updated on Nov 3, 2026. A date after a source is the day we read it. Versions and steps follow the official project; if they differ, the official source wins.

More ports

See every native PC version of a console game in our recompiled games list, browse all PC ports of console games, or go back to the full list of ported games.

Julius and Augustus (Caesar III re-implementations)

Every version of Caesar III 2

Julius and Augustus (Caesar III re-implementations)This page

Augustus