Each Home City Card sends units to the colony or resource crates or provides upgrades to a player's units, economy or buildings. There are five categories of home city cards, with up to twenty cards allowed in a deck in Age of Empires III, and up to twenty-five (an additional one per ten home city levels) allowed in a deck in the expansions. Each Age can hold ten cards in skirmishes and in supremacy as of the latest patch while the single player campaign only allows nine cards per row.