High Medieval: Adventure Through History
A historical fantasy RPG that adds fantasy and magical elements to late medieval Europe. It uses the ""Omni RPG System¸"" also released under Wizards of the Coast's Open Game License. Action resolution uses skill or attribute minus difficulty + 1d20¸ interpreting the results on a universal degree of success table. - A description from https://darkshire.net/jhkim/rpg/encyclopedia/ with kind permission of John H. Kim"