The system was somewhat like Dungeons & Dragons with character classes and levels. Classes available included Animist (Cleric), Bard, Fighter, Mage, Ranger and Scout (Rogue). The system departed in having a highly detailed combat and magic system.
In the MERP game system, attributes are rating between 0 and 100, and skills can surpass these limits (under 0 or over 100). An attack roll would consist of a percentile roll + skill rating + attribute rating - target's dodge rating. This result was looked up on a table against the victim's armor type (leather/plate). Most hits in combat would cause a 'critical' which would be rolled and looked up on separate tables. For a time these criticals are quite entertaining due to their variety and creativeness. For others the task of adding and subtracting high numbers to then consult a table was the height of roll-playing, not role-playing.
Spell casters had the unique advantage in MERP that they learned list of 10 spells (1 per level) as a unit. Once a character learned the Healing list, he would be able to cast increasingly better healing spells as his level increased.
The setting for this game predates the War of the Ring by around 1400 years and as such it represented a version of Middle-earth radically different to that seen in The Lord of the Rings trilogy or The Hobbit.
The game had a loyal and strong following.
This was the first licensed role-playing game based on this setting, the second was the Lord of the Rings Roleplaying Game from Decipher Inc