Version 1.50.11

Fan patch for Master of Orion II: Battle at Antares.
Contains MOO2 Launcher and ICE 18a.

Installation FAQ & Changelog

7617 kB; 1775 downloads

Patches Overview

1.31 Official Patch

Master of Orion II: Battle at Antares version 1.1 was available in North American retail stores from November 22, 1996. The first patch, version 1.2, was quicky released to the web three days later. Patch version 1.3 was revealed to the world in March 1997. With it came the release of German, French, Spanish and Italian translations of the game. For the English, German and French versions, 1.31 patches were released on April 11, 1997. After that, an integrated executable was built for the Spanish and Italian languages (2-in-1) that contained a few undocumented bug fixes but still carried the same version number 1.31. Towards the end of the year, a 5-in-1 version became available, again as a version 1.31, bringing these additional bug fixes to the other three languages. The English and German 1.31 patches (April 11 versions) are available in the download section below.

1.1-1.31 changelog.

1.31 Russian Fan Patch

A Russian language version of the 1.31 patch was made by Grig de Griz during 2006-2007. This version is an add-on to the official 1.31 version and does not replace any original game files. To play the Russian version of the game, start the file "MOO2_RUS.EXE" in DOSBox after unzipping the pack into your MOO2 folder. Available in the download section below.

Russian version 1.31 readme.

1.40 English Fan Patch

The English DOS version sold online is fan patch 1.40b23 from May 2006. Information about this patch can be found in Lord Brazen's 1.40 patch FAQ.

1.50 Fan Patch

Progressive fan patch for the English, German, French, Spanish and Italian DOS versions of Master of Orion 2. Fixes most known crashes, stalls and network synchronization errors, as well as an abundance of interface and game rule bugs. Game help texts have been corrected and expanded upon.

The patch introduces new features like the option to play against a random number of opponents, and interface enhancements that reduce micromanagement like new keyboard shortcuts and editable build queue lists. It has integrated mapgen functionality and supports modding via plain text configuration files so you can easily customize your game! Since patch version 1.50.7 there is (limited) Lua scripting support.

The distribution comes with the mods 1.50 improved, ICE-M, ICE-X and Melee, as well as several mapmods. The game can also be played in a classic mode. In this mode no game rule changes are made via config. Some buggy mechanics are unaltered to preserve classic strategies; for example Fighters retain the +1 extra damage for energy beams (for blitz games) and the buggy Lightning Field guarantees survival of 50% of missiles in a stack (for Guardian rush games).

The included MOO2 Launcher allows you to easily configure several DOSBox options and select your mod and mapmod of choice before running the game. The Launcher defaults to '1.50 improved' after initial installation.

The big manual contains detailed descriptions of bug fixes, new game mechanics, modding options, scripting support and notes on various game mechanics.

1.50 changelog.


List of downloadable patches:

Patch version Language Released Size (kB)
1.50.11 en, de, fr, es, it 31 Mar 2018 7617 1775 en, de, fr, es, it 18 Mar 2017 4787 2398
1.31 en 11 Apr 1997 3350 814
1.31 de 11 Apr 1997 2342 352
1.31 ru 9 Apr 2007 1455 88

Mods & Maps

1.50 Improved

The default choice in Launcher, 1.50 improved enhances classic with Ship Initiative II (YouTube video), interactive combat stats, updated AI ship designs, removal of quirky behaviors, several tweaks, and an AI that can research hyper-advanced techs.

1.50 improved (pdf).

ICE 18a

The ICE mod changes many aspects of the game, aiming to create a more challenging game: Stronger AI opposition; revalued race ability costs (46 picks instead of 20); revamped tech tree; beefed up Guardian; more threatening Antarans and a grand finale when invading the Antaran home world!

Custom Race Design
All attributes, including governments and special abilities have been revalued. Some are more expensive like Unification and Lithovore, and some are cheaper like Ship Defense and Ground Combat bonuses. In classic MOO2 you can design a race with up to 20 picks (10 base picks and 10 negatives). In ICE there are up to 46 picks available (24 base and 22 negatives). This allows for a more precise valuation of the different traits. The 6 extra picks make construction of very powerful custom races possible. The stock races have been redesigned to match the new picks.

Custom Race

Mind Control
The most broken trait in classic MOO2 must be the Telepathic ability at a 6 pick cost. In ICE, Mind Control requires a Titan or Doom Star class ship instead of a Cruiser, so quick tele-blitz games are no longer possible.

Population Capacities
Population limits have been increased and all climates and planet sizes have different max pops. A standard medium Terran world will now support 15 instead of 12 population units. There are no more planets with max. 1 pop! Tiny radiated and toxic planets have the lowest population capacities and can support up to 2 population units.

Technology Tree
In ICE you need to invest 20% more research points to complete the entire tech tree. The placement of various technologies in the tree has changed, but I tried not to stray too far from the classic tree. The crucial tech Research Labs has been isolated. This helps the A.I. and is good for Uncreative races but lowers the value of being Creative. Fighters are available a little later in the tree. Bombs have been moved from the Power to the Physics branch and many techs have moved positions in the Fields branch.

Tech Tree

Planetary Defenses
Star Bases, Battlestations and Star Fortresses are stronger, have more space for weaponry, and more Marines onboard. All bases have a reinforced hull by design. Researching Reinforced Hull technology does not increase orbital platforms structure points. Satellites and Missiles Bases can be fitted with torpedoes. Missile Base and Ground Batteries have slightly more space for weapons. Fighter Garrison has been upgraded and launches fighters every turn instead of every 10 turns. The Artemis System Net in ICE is much stronger than the default one.

All ships except the Frigate have 20% more base space available in ICE. The Battle Pods bonus has been decreased from 50% to 25%, so total space stays the same (1.00*1.50 = 1.20*1.25). A.I. opponents that miss out on Battle Pods now have a smaller disadvantage. Note that the value of Megafluxers has increased, as the 25% bonus is calculated over the larger base space.

A.I.'s design their ships according to a few templates, which I have adjusted to improve chances that they show up with something that can actually crack a nut.

Stealth Detection
A new feature in ICE is 'Stealth detection'. In Standard MOO2, you can only detect stealthy ships (Darloks) when you are Omniscient. In ICE you can detect cloaked ships with advanced scanning technologies.

Orion & Antares
The Guardian has a Class X Shield, making it much harder to kill. Be prepared! EMG Merculite missiles were the quickest way to defeat the Guardian in classic MOO2 but they will not have the desired effect in ICE.

The Antarans have a few surprises waiting for you at their home world. Compared to the original, it is really hard to win this way and requires advanced ships. I like a grand finale!

ICE-X boasts AI opponents with more raw power, further increasing the difficulty level. The Impossible level of ICE-X is for expert players, you'd better know what you are doing!

Both ICE-M and ICE-X are included in the 1.50 download and you can choose your preferred version in the Launcher.

ICE strategy and walkthroughs on Civfanatics.

ICE changelog.


New, experimental mod for 2-player tactical combat. The galaxy has 4 systems: 2 home systems, Orion and a neutral system. Each player can build 30 command points worth of ships. Then both players fly to the neutral system and duke it out. No retreating! The loser designs new ships and can make designs to counter his opponents ships while the winner brings his surviving ships into the next fight supplemented with new ships (for again 30 command points total). Fight!

Note that this mod is in development and might cause crashes/freezes from time to time. It is important to start each new game in a small galaxy and with 2 players, otherwise the game can stall!

Setting up Multiplayer over the Internet.

Defensive Anti-Blitz Mod

In response to a request on Reddit, I have adapted the old Defensive Anti-Blitz Mod by Jukka Mikkonen to run on 1.50. I haven't changed it much, mostly enabled the new 1.50 combat mechanics and corrected a few issues with the original mod. DAB version 5 is for patch version 1.50.11 or higher. Highlights: Missile Base has 800 (instead of 300) space units - An upgrade to ship hit points, and even larger for star bases - Strong ground installation with 10x the hit points - Severely upgraded space monsters & Guardian of Orion, damagewise - Antarans should prove to be a threat once again - A few automatic techs, such as Auto-Factory, Fighter Bays, Fighter Garrison, Reinforced Hull and Heavy Armor. v5 (124 downloads; 88 kB)


Information about this mod can be found on the Orion Nebula. Note that VDC runs on patch version (4787 kB).

Open Challenge 1 by Kraft57

You are an uncreative telepath, starting in a corner of a large galaxy. Can you win within 100 turns? To play, download the zip and extract. It contains 2 save games, one for version 1.31/1.40 and one for v1.50. Rename the appropriate version to SAVE10.GAM and copy it to your MOO2 folder. Then load save 10 from the universal menu and start! (839 downloads; 95 kB)

Open Challenge 2 by Rocco

You play an uncreative race, starting in an isolated region of space. Can you get out, and if you do what resistance will you meet? To play, download the file, rename it to SAVE10.GAM and copy it to your MOO2 folder. Then load save 10 from the universal menu and start!
SAVE10_OC2_ROCCO.GAM (889 downloads; 204 kB)

3 Stars Puzzle

You start in a system with five good planets, but the galaxy only contains three stars! To play this map, download the .gam file, rename it to SAVE1.GAM and copy it to your MOO2 folder. Then load the save "3 Stars" from the universal menu and start!
SAVE1_3.GAM (862 downloads; 204 kB)

The Tragedy of Orion

You start in the corner of a galaxy that has a huge black hole in the middle. To play this map, download the .gam file, rename it to SAVE1.GAM and copy it to your MOO2 folder. Then load the save "The Tragedy of Orion" from the universal menu and start!
SAVE1_TRAGEDY.GAM (227 downloads; 204 kB)

Race Randomizer

Looking for inspiration for your next game?
Then randomize your next custom race build!


Refresh if you are not convinced.

ICE 18:

Refresh if you are not convinced.


Corion2 1.1.1
savegame editor for 1.50; 153 kB; 1842 downloads; readme

MOO2 Workshop
editor suite; 2720 kB; 1724 downloads; readme

HxD Freeware
HEX editor from (external link)