Old-School Essentials Notes on the 2026 Update

The 2026 OSE core books (Player's Book + Referee's Book) include a number of clarifications, minor rules fixes, and new optional rules. This document summarises the most significant changes for players with prior versions of OSE to use in their games, if desired.

• New optional rules (3 pages). Advanced Hit Dice, Age and Lifespan, Attacking When Blinded, Fighter Combat Dominance, Hovering at Death's Door, Increasing Back-Stab Damage, Magic Armour Size, Magic Swords and Daggers Shedding Light, No Alignment Languages, Training, Weapon Restrictions For Small Characters, XP For Magic Items.
  
• Rules additions (1/2 page). Combat Aptitude, Poison Antidotes, Spell Caster Specialist.
• Rules clarifications (1/2 page). Air Elemental, Green Slime, Stun.
• Rules changes (1 page). Attacking From Behind, Multiple Classes, Secondary Skills, Slow Weapons, Waterborne Adventuring, Wilderness Adventuring.
• Tweaks to AD&D-inspired classes (1 page). Assassin, Barbarian, Knight, Ranger.