A 24-page course on turning a vague idea into testable rules: the parts of a written plan, rewriting vague rules, step-by-step manual backtesting with bar replay, sample size, look-ahead and overfitting traps, core metrics like expectancy and drawdown, paper forward testing, and honest review. Includes a 5-page plan template, backtest log, and changelog. No strategy is presented as profitable. Risk note: most day traders lose money; education only, not financial advice.