This 32-page rulebook expands Melee, providing rules for movement, facing, initiative, surprise, lots of information about weapons and combat including peculiar weapons, left-hand weapons, thrown weapons, missile weapons, shield-rush attacks, hand-to-hand combat, trampling, sweeping blows, ambush, berserking, dropped and broken weapons, fire, poison, gunpowder, and mounted combat.
Advanced Melee is part of The Fantasy Trip system, which also includes Melee, Wizard, Advanced Wizard, and In The Labyrinth.
Note that Steve Jackson has regained rights to TFT and is publishing a new version. The new Advanced Melee will be part of the ItL book, and more information can be found here...
https://rpggeek.com/rpgitem/256884/fantasy-trip-legacy-edition