Editing Iron Crown Enterprises

Iron Crown Enterprises was founded by some sadistic college kids in 1980. They decided that AD&D wasn't clunky enough so they wrote up a couple supplement books to add a more simulationist bent to the game. So if you wanted the ultimate in realism, you would go buy a copy of Arms Law, make your attack, then roll of 47.3 tables to find out what happened. This made the complicated task of swinging a sword much more understandable and it only took 40 minutes! Progress!

When the guys at I.C.E. weren't making your game systems more complicated, they were making their own complicated game systems. Granted, the detail was unsurpassed, but it came at the expense of simplicity and playability. Rolemaster and Spacemaster were undoubtedly detailed and fantastic in scope, but they were beat out by more streamlined games. Iron Crown went bankrupt a few years ago and are now owned by a company named Mjolnir something or other. 

Notably, Iron Crown got the license from the Tolkien estate to make an RPG based on the works of Tolkien.
The Middle-Earth Role Playing System, or MERPS, was a more fluid interpretation of their Rolemaster rules, and enjoyed moderate success.

I.C.E. products are still being made and sold, but to a niche market.