Heroes of Might and Magic II

Heroes of Might and Magic II: The Succession Wars is a turn-based strategy video game developed by Jon Van Caneghem through New World Computing and published in 1996 by the 3DO Company. The game is the second installment of the Heroes of Might and Magic series and is typically credited as the breakout game for the series. Heroes II was voted the sixth-best PC game of all time by PC Gamer in May 1997.

FHeroes2 is a free implementation of the Heroes of Might and Magic II engine.

Minimum system requirements: 

A retail copy of Heroes of Might and Magic II: The Succession Wars and the FHeroes2 engine