UOR based PVP with additions to various skills to provide a wider range of templates that can compete.
In a nutshell:

• Stun Mages: Wrestling + Anatomy allows Stun Punch attack
• Thiefs: Wrestling + Armslore allows Disarm attack
• Evaluating intelligence >= 80 + Anatomy >= 80 accounts as wrestling (old OSI UOR based mechanic)
• Alchemy gives bonuses for potion usage (effect strenght and duration)
• Tank Mages: All melee weapons have a nerfed version of the “insta hit”
• Lumberjacking: Gives a bonus when using an axe
• Bowcrafting: Gives a damage bonus when using a bow
• Carpentry: Gives a damage bonus when using wooden non-ranged weapons.
• Mining: Gives bonuses when using hammer picks and war axes
• Peacemaking: Along with taking the victim out of war mode, it also disturbes magical spells

• Milita(Faction) based
• Red vs Blue
• Guild Wars

• Townwars
• Capture the Flag
• Duel Pits