
The i20 ruleset is an adaptation of d20 2014 PHB that re-balances and adds mechanics to reflect the specific mechanics and flavor for the particular Gritty Realism sought by the designers. There are key elements of all of this that play testing has show are both preferred almost universally, and easily adopted without introducing too much to the base d20 system as it is. This will be referred to as “i20 Light.”
Particularly the elements of cost of armor & maintenance, an increased level of lethality, dynamic combat using Resilience of items with a scaled result that emphasizes quality over randomness. Its enough to emphasize elements of the particular flavor of Gritty Realism desired, without it being as cumbersome as rewriting the fundamental elements to be more integrated and game-balanced with them.
Tutelage & Obligations; Patrons, trainer, clergy, master-apprentice, etc. especially for mystical empowerment. Multi-classing is not just “taking your next level as X”.