This system was shared between the Lord of the Rings Adventure Game, Tolkien Quest and Middle-Earth Quest books, as well as creature and NPC stats in some MERP 2nd Edition products.
It is a simplified, level-less system that makes use of two six-sided dice for all rolls. There are 9 character types available, each a combination of what other systems would split into "Race" and "Class" (such as "Hobbit Scout" or "Human Ranger"). Each of these is then defined by 12 Stats, including both what other systems would call "Attributes" (defining a character's mental and physical characteristics) and "Skills" (defining a character's training and talent for various tasks like melee combat or magic).
PDFs of Lord of the Rings Adventure Game (LOR) books can be found in various places on the internet.
Middle-Earth Adventure Game (MEAG) is compatible with with all LOR materials, plus MERP books
published after about 1988 have LOR stats in the back that will work with MEAG.