From "2012 Silver Jubilee System Update:"
A lot of new material from the Minotaur webzine has been added to the M&M Companion, bumping its page count from 43 to 50 – exactly like the Players Manual and the Maze Masters Guide!
Chapter I: Character Options
This chapter includes the variant, “liberated” version of the Amazon class – but no longer includes the Heroic Option (no longer an option but a standard rule integrated into the Players Manual) and the Noble Heritage table (which has no raison d’être with the renovated Noble class).
Chapter II: Divine Agents
The Luck requirement for divine agent status has been lowered from 20 to 18 – which means that some renovated Nobles (whose Luck can no longer be above 18 at level 1) can still start the game as divine agents – a privilege which is now extended to those all characters, provided they meet the 18+ requirement in Luck and a favored attribute.
Chapter III: Combat Options
This chapter now includes rules for knife-throwing and staff-fighting, unarmed combat additions and optional rules on weapons and armor – including Luke G. Reynard’s historical weapons and armor variants as well as his optional rules on armor and relative Size' in melee combat.
Chapter IV: Magic Options
This chapter now includes the Revised version of Erik Sieurin’s Beastmaster class.
The Light and Darkness powers now take into account the new magic range rules; the Cloak of Shadows power has also been slightly redefined.
Chapter V: Religious Options
No changes here.
Chapter VI: Miscellaneous Rules
This chapter now includes rules for curing poison.