To Tread The Jeweled Thrones
PCs are Human
Using the re-skinning from Death Slaves of Eternity: Halflings are Freebooters (minus the small size and infravision); Elves are Cultists (minus the iron allergy, infravision, etc); Dwarves are Soldiers (minus the small size and infravision).
Shields Shall Be Splendid
|Shield||AC bonus||Check Penalty|
Using a shield and armor within 3 bonus of each other provides AC equal to the better of the two, plus 1. Using shield and armor more than 3 different, like full plate and a buckler, or leather armor and a tower shield just provides the better of the two bonuses. The Check Penalty is the worse of the two, minus 1, regardless of how close in bonus they are.
Using these rules, all the AC bonuses and check penalties stay the same for existing characters if they like, but there’s the option of shedding a bunch of armor to increase mobility and fit in better with actual historical shield/armor mixes such as Hoplon plus linen linothorax or just greaves and helmet, or targe and leather or hide, or even fantasy comic book targe or buckler and chainmail bikini. The bonuses are chosen with an eye on providing even min-maxers an incentive to keep to vaguely plausible combinations, even if plausible includes the likes of Frazetta’s Conan or Frank Thorne’s Sonja.
Instead of the various +2, -1, +1, etc. combat modifiers, we're swiping Advantage/Disadvantage from D&D 5e, except moving up and down the dice-chain instead of rolling multiple dice. So some situation the Judge deems justifying Advantage would change a d20 roll to a d24, or Disadvantage would be d16.
Per the Lankhmar optional rules, you start a session with 1 point of Fleeting Luck; it can be spent as normal Luck. Any roll of 20 grants you an additional point of Fleeting Luck, but any roll of 1 by any player causes all Fleeting Luck to evaporate. Use it or lose it.
Luck as Healing
If your party doesn't have a Cleric, you can spend a point of luck once per combat to spend a full round and examine your wounds, realizing they aren't as bad as you thought (gain back 1 HP die + Stamina mods). Once per day after a battle you can spend 1d3 turns (not rounds) and get back 1 HD + Stamina Mods + level (but only once for a particular set of wounds, even if you're not all healed up by the next day).