Wargaming was invented in Prussia near the end of the 18th century. The earliest wargames were based on chess; the pieces represented real military units (artillery, cavalry, etc.) and squares on the board were color-coded to represent different terrain types. Later wargames used realistic maps over which troop pieces could move in a free-form manner, and instead of chess-like sculpted pieces they used little rectangular blocks because they were played at smaller scales (e.g. 1:8000). The Prussian army formally adopted wargaming as a training tool in 1824. After Prussia defeated France in the Franco-Prussian War of 1870, wargaming spread around the world and was played enthusiastically by both officers and civilians.