Most races from the Player's Handbook (PHB) and Mordenkainen Presents: Monsters of the Multiverse (MPMM) are allowed. The following official races are banned; some are replaced:
Halflings are replaced with Kender (from UA: Heroes of Krynn Revisited)
Dragonborn are replaced by Draconians (see Krynn's Homebrew page, when I eventually add them)
Orcs and Half-Orcs are banned and not replaced.
Classes, Subclasses, and Feats from the PHB, Xanathar's Guide to Everything (XGE), and Fizban's Treasury of Dragons are allowed.
Any material from other published sources requires DM approval, but will probably be approved if it is not from a setting-specific sourcebook.
If your race's equivalent NPC statblock is Tiny or Large, you can be that size instead of Small or Medium.
For your background, you may choose any two skill proficiencies and any two tool/weapon proficiencies or languages.
When rolling stats, roll 4d6 drop lowest six times. You may reroll if the total is less than 75.
When creating a low-level character, you start with the equipment provided in your class features and background, as well as the starting wealth listed for your class.
If you are creating a character at level 5 or higher, you get a different amount of money with which to purchase starting equipment, and potentially get a free magic item. Use the following list instead of your class' starting wealth and equipment:
Level 5-8: 500 + 1d10×25 gp
Level 9-12: 2,500 + 1d10×125 gp, 1 uncommon
Level 13-16: 5,000 + 1d10×250 gp, 1 uncommon, 1 rare
Level 17-20: 20,000 + 1d10×1,000 gp, 1 uncommon, 1 rare, 1 very rare
Spells: If there is one specific spell that fits perfectly for your build, that isn't on your class' spell list, let me know, and I may allow you to take it as a class spell regardless.
I have not yet finalized every single house rule for this setting. However, here is a preview of the most important changes, so that you can more easily decide which setting to start in for the first arc of the campaign. In general, playing in Dragonlance is designed to feel like playing a 3.5e DnD/Pathfinder game - extreme high fantasy with high-end feats being possible. Magic is rare and legendary, but powerful.
Monsters are more powerful, especially dragons
Certain spells can interact with Alignment (such as Detect Evil and Good)
Healing potions restore the maximum possible roll
Major EXP is given for defeating powerful monsters.
Critical Hits are more powerful, but need to be "confirmed."
Critical Successes and Failures apply to skill checks.
Inspiration is replaced by "Plot Points": Characters can spend a Plot Point to add some interesting element to a situation
"Plot Armor:" characters can spend multiple hit dice and gain a Lingering Injury instead of dropping unconscious
The creation of magic items is a very personalized endeavor, and as such, every magic item that originates here has a meaningful story behind it, and usually has unique mechanics. As a result, "Common" rarity magic items are ironically extremely rare on Krynn.