Can source material such as from Castles be used in a product you are creating for sale.
Was looking to create an adventure (Will charge for it) for a TTRPG I play in the crusading period. I like the Krak de Chevaliers in the castles product (Which I legally own). My question is can this (e.g. exported JPG) be used in the adventure I write ? Or can I redraw it but use the information in the original and still be okay?