WorldSim runs Monte Carlo simulations across socio-economic indicators for 195 countries, producing full probability distributions (P10/P50/P90) instead of single-point forecasts. Over 100 structural coupling rules connect variables causally: shock energy prices and inflation, rates, housing, and debt cascade automatically. Three scenario paths (Better/Average/Shock), user-controlled bias overlays, and reproducible runs. Built for macro analysts, policy teams, and country risk professionals.