Classic computer-based fantasy role-playing game released in 1990 by Origin Systems. Its main amtgard interest is that one of the lead designers, Dr. Cat, played Amtgard in Barad Duin, and populated much of the game with amtgarders from that group. Several other people at Origin Systems also played Amtgard there including artist Manda Dee. Richard Garriot (aka Lord British aka Shamino) had long populated Ultima games with people from the local SCA group as well.
Among the people from Barad Duin who appear in Ultima VI:
(list is far from complete)