Or: what broke on my first three attempts so you don't have to repeat it Step 0. Before you write a single line of code I've built two prediction markets from scratch. The first one crashed on testnet. The second one launched but had zero users for two months. The third one? Actually works. Here's what I learned in the process. Ask yourself three boring but critical questions: Binary outcomes (Yes/No) or multiple choices? Who decides the truth? (centralized admin, oracle, token holders?) How does liquidity enter the system on day one? Don't skip these. I skipped #2 on my first try and ended up hardcoding the resolution logic. Guess what happened when a market ended in a tie? Panic. Tears. Rewrites. Step 1. The simplest market math that doesn't suck You'll hear about LMSR, logarithmic markets, and constant function market makers. Ignore the noise. Start with this — a basic LMSR implementation you can actually run: python import math class SimpleMarket : def __init__ ( self , liquidity = 100 ): self .…