Monstrous Menagerie II: Hordes & Heroes has a launch date! Mark your calendars for November 12th, 2024. 300+ more monsters for your D&D 2024, or Level Up: Advanced 5th Edition games, plus new horde rules and rules for heroic monsters who level up alongside you--whether they be allies, companions, or foes! Click here to follow on Kickstarter!
I need a rules system to be complex enough to be part of the escapism without being overwhelming to the point of being immersion breaking from looking up rulings all the time. I find this usually comes from a deep pool of character options and a moderately robust combat system.
I need the rules to be Intuitive (this is where D&D falls apart for me), Elegant (simple, smart) and Robust (hackable, complimentary for the scene, theme and setting).
The rules mechanics need to fit the style and feel of the campaign setting. As long as that fits, generally I'm all good.
As an example... Dark Sun worked so well under the 2nd edition of AD&D. Attempts to play and run that setting under 3.X and PF have failed because the same overall feel and immersion isn't there under that sort of rules system.