I would like to try to run some classic D&D modules like “Keep on the borderlands” or some OSR games like “Barrowmaze”
But to do this properly i need a way to convert monsters to ICRPG, most notably the fact that in D&D players gain HP when leveling, and monsters reflect that. In ICRPG players would generally have same HP throughout the whole game, while in the modules monsters would reflect HP increase of players.
I am looking for idea. How to convert monsters. What to do with their hit dice ? How to reflect this into ICRPG, by keeping the monster equally challenging, but now on level playing field with player characters.