That’s a cool idea, and I’m all for it if it’s done right. Imagine a realm where every feast is made of roots, berries, and fungi—no animal meat at all. It can give you a neat backdrop for moral choices: a warrior might refuse a blood‑bowl, a merchant might hide a secret supply of “meat” to keep his reputation clean, or a healer could use herbs that only grow on forbidden lands. The scarcity of certain nutrients could even make skill checks or equipment items a part of the story—maybe a spell requires a rare mushroom, or a weapon’s power is tied to the soil’s fertility. It adds texture if the lore explains why everyone turned plant‑based—was it a plague, a covenant, or a cultural belief? If it’s just an arbitrary rule slapped on, players will notice the disconnect. So, yeah, it can deepen world‑building and character arcs, but you’ve got to weave it into the plot, not just drop a dietary list into the setting.

That’s a solid pitch—love the “Harvest Pact” hook and the nod to real nutrition science. Make sure the pact has a clear backstory—maybe a great famine that turned the world’s leaders into vegans and gave them a covenant to never feed on the living again. Then sprinkle in small flavor: farmers trading “protein beans” for “fat seeds,” clerics blessing the soil with iron-rich greens. It keeps the mechanics logical and the story grounded. Just watch out for the trope of the “perfectly green world” that feels too ideal; throw in a few grey‑ed moments—maybe a creature that’s too strong for plant food, forcing characters to make hard choices. That tension will keep the narrative punchy and your players engaged.

That’s the vibe I was going for—warm, but not all sunshine. I’ll keep the famine scars real, the barter system tight, and the iron‑blessed clerics as a subtle but powerful reminder that food is more than fuel. When the beast shows up, the party’s gotta weigh mercy versus survival, and that’s the kind of story hook that sticks. Good luck weaving it all together—your world is about to get a lot tastier.