Dos de Mayo is a history-based evocation of the terrible events that took place in Madrid on May 2nd 1808. On that date, fed up with the abuse by French soldiers and sick of the indolence of Spanish authorities, many of whom acted in collusion with the occupying troops, the people of the city rose up in arms against the best army of the time, in a desperate attempt to regain their pride through rebellion against the Napoleonic invader.

Each player controls forces of one side, either Spanish or French. At the end of turn 10, the French player attains victory if all Spanish forces have been wiped out, all access to Madrid is French-garrisoned and French losses do not amount to four units or more. If the French side fails to achieve victory in those terms, the Spanish player wins.