The Super Fleet Cheat
Go into "Master of Orion 3\GameDataSets\Classic_01\GameData\Common\Spreadsheets" and dig out the "TaskForceRules.txt" from the Ships.mob
At the very beggining, you'll see the rules on various take force sizes. Under the line that says "Armada TSKSIZE5 15 18 2 4 6" simply add a new line:
"Fleet TSKSIZE6 1 100 0 0 0"
Now when you play the game, a new line will appear on the Task Force Creation pull down menu below Armada that says "TSKSZE6." What is TSKSZE6? Anything you want it to be! Up to 100 ships, no minimum or maximum required in any ring, and the formation type doesn't even have to match the actual ships used (very useful when making IF formations into Long Range Attack fleets so that they'll stick around after they've fired off their missiles, or making a LR attack fleet act like a SR attack fleet instead).
Laugh in the face of the enemy's 180 ship (10x18) battle limit as you field up to 1,000 ships at a time! (Note: this may overwhelm your CPU ... personally, I try not to go over 40 ships to a fleet, just to keep my computer from having an anurism)