Rules can vary greatly between game systems; both in complexity and era. Historical rulesets range from the ancient and medieval ships to the fleets of the Age of Sail and the modern era. Often the hobbyists have to provide their own models of ships. The 1972 game, Don't Give Up The Ship!, called for pencil and paper, six-sided dice, rulers and protractors, and model ships, ideally of 1:1200 scale. The elaborate rules cover morale, sinking, fires, broken masts, and boarding. Dice determined wind speed and direction, and hence the ship's speed and the use of its cannon by measuring angles with the protractor.