From the announcement:
Our popular system for ancients and medieval wargames goes digital!
The rulebook is now available at Wargames Vault at 14.99 USD.
This is just a new purchase option as the printed version will remain available as usual.
Impetus is a grand tactical set that allow you to play over 3,000 years of history, from Ancient Sumeria to the Great Italian Wars. It is suitable for any scale of figures,from 2mm to 28mm (and over) thanks to its popular basing that allow you to recreate small dioramas.
The rulebook includes also 16 starter lists (Macedonians, Persians, Greeks, Mid Republican Romans, Carthaginians, Gauls, Caesar’s Romans, Parthians, Crusaders, Saladin’s Ayyubids, Teutonic Orders, Mongols, 100YW French, 100YW English, Francis I French, Charles V Imperials).
Many more lists are available from supplements called Extra Impetus. There are also several free lists (beta lists) available for free on the website.