Great War Spearhead does require ownership of Spearhead to play it.Units are companies, as armies were much larger in WWI. The scale is 1/285 or 15mm.The rules may be used for Russo-Japanese War actions as well. ToEs are included for all major (and many minor) WWI countries.Special rules allow for realistic portrayal of trench warfare, pre-battle bombardments, and use of gas.Expands: Spearhead - BoardGameGeek