My Recommendations. I have placed adventure modules at the end, since they can pretty much be run in any order. For those, go by publish date. 1. Players Handbook, it just gives you the full set of rules 2. Monster Manual, full set of regular monsters, with tokens 3. Xanathar's Guide, more spells, more character class options 4. Mordekaininen Tome, More monsters 5. Volo's Guide, last because it has not been incorporated into the Charactermancer yet. 6. Guildmaster's Guide to Ravnica, necessary only if you are planning a Ravnica campagin Check to see which products are contained within others. If you buy Tales from the Yawning portal, you don't need to buy any of the sub adventures (ex. White Plume Mountain) Adventure Publish order (Not all of these are available on Roll20 yet.) Lost Mines of Phandelver Tyranny of Dragons - Hoard of the Dragon Queen Tyranny of Dragons Elemental Evil - Princes of the Apocalypse Rage of Demons - Out of the Abyss Curse of Strahd Storm King's Thunder Tales from the Yawning Portal Tomb of Annihilation Waterdeep Dragonheist Waterdeep Dungeon of the Mad Mage Ghosts of Saltmarsh (coming soon)