From the back cover of the rules: Crusader is a set of wargames rules that allow you to game some of the greatest battles in history from Biblical times to the Medieval period. Although written with 28mm figures in mind the rules are stand-based and so easily translate to any scale of model. The rules cater for many popular basing methods so there is absolutely no need to re-base your figures to be able to play Crusader. At the heart of the rules is the concept that you are representing units of troops in battle rather than individual warriors. Dispensing with the traditional phases within a turn the unit-based mechanics allow for a fluid game that simulates the quality and training of troops rather than the abilities of a few super characters. The rules have been created with the flexibility to allow armies from widely differing time periods to fight against each other through the use of a consistent points system. So if you want to fight William the Conqueror's Norman Army against Alexander's Macedonians feel free!