Retro RPG: Rolemaster
Rolemaster is a role-playing game published by Iron Crown Enterprises. Rolemaster has come in four separate editions. The third edition, first published in 1995, is also known as the Rolemaster Standard System (or RMSS for short).
Rolemaster is a fairly numbers-heavy game that also relies on the use of a lot of tables. Most notable are its notorious 'critical hit' charts, which are subdivided by damage type and describe various horrific wounds in graphic detail. If you're looking for a highly detailed and fairly complex system, Rolemaster has a great deal to recommend it. The rules are fairly well organised and very flexible, easily adaptable to a wide variety of situations. On the other hand, if you're not one for tables and calculations, it's probably not going to ring your bell.