Horseclans

1. The Coming of the Horseclans (1975)
2. Swords of the Horseclans (1976)
3. Revenge of the Horseclans (1977)
4. A Cat of Silvery Hue (1979)
5. The Savage Mountains (1979)
6. The Patrimony (1980)
7. Horseclans Odyssey (1981)
8. The Death of a Legend (1981)
9. The Witch Goddess (1982)
10. Bili the Axe (1982)
11. Champion of the Last Battle (1983)
12. A Woman of the Horseclans (1983)
13. Horses of the North (1985)
14. A Man Called Milo Morai (1986)
15. The Memories of Milo Morai (1986)
16. Trumpets of War (1987)
17. Madman's Army (1987)
18. The Clan of the Cats (1988)

Castaways in Time

1. Castaways in Time (1980)
2. The Seven Magical Jewels of Ireland (1984)
3. Of Quests and Kings (1986)
4. Of Chiefs and Champions (1987)
5. Of Myths and Monsters (1988)
6. Of Beginnings and Endings (1989)

Stairway to Forever

1. The Stairway to Forever (1988)
2. Monsters and Magicians (1988)
3. Guideposts to Danger (unpublished)

Anthologies edited

Magic in Ithkar (with Andre Norton)

1. Magic in Ithkar (1985)
2. Magic in Ithkar 2 (1985)
3. Magic in Ithkar 3 (1987)
4. Magic in Ithkar 4 (1987)

Other

• Barbarians (1986), ed. (with Martin H. Greenberg and Charles G. Waugh)
• Barbarians II (1987), ed. (with Pamela Crippen-Adams and Martin H. Greenberg)
• Friends of the Horseclans (1987), ed. (with Pamela Crippen-Adams)
• Friends of the Horseclans II (1989), ed. (with Pamela Crippen-Adams)
• Robert Adams' Book of Alternate Worlds (1987), ed. (with Pamela Crippen-Adams and Martin H. Greenberg)
• Hunger for Horror (1988), ed. (with Pamela Crippen-Adams and Martin H. Greenberg)
• Robert Adams' Book of Soldiers (1988) (with Pamela Crippen-Adams and Martin H. Greenberg)
• Alternatives (1989) (with Pamela Crippen-Adams)
• Phantom Regiments (1990), ed. (with Pamela Crippen-Adams and Martin H. Greenberg)

• New General Catalog of Old Books and Authors