| YEAR | TITLE | TYPE | SERIES |
| 1961 | The Warlock in Spite of Himself | Novel | Warlock of Gramarye |
| 1971 | King Kobold | Novel | Warlock of Gramarye |
| 1979 | A Wizard in Bedlam | Novel | Rogue Wizard |
| 1982 | The Warlock Unlocked | Novel | Warlock of Gramarye |
| 1983 | Escape Velocity | Novel | DDT-verse |
| 1984 | King Kobold Revived | Novel | Warlock of Gramarye |
| 1985 | The Warlock Enraged | Novel | Warlock of Gramarye |
| 1986 | To the Magic Born | Omnibus | Warlock of Gramarye |
| The Warlock Enlarged | Omnibus | Warlock of Gramarye | |
| The Warlock Wandering | Novel | Warlock of Gramarye | |
| The Warlock Is Missing | Novel | Warlock of Gramarye | |
| Her Majesty's Wizard | Novel | Wizard in Rhyme | |
| 1987 | The Warlock Heretical | Novel | Warlock of Gramarye |
| 1988 | The Warlock's Companion | Novel | Warlock of Gramarye |
| The Warlock's Night Out | Omnibus | Warlock of Gramarye | |
| 1989 | The Warlock Insane | Novel | Warlock of Gramarye |
| Odd Warlock Out | Omnibus | Warlock of Gramarye | |
| 1990 | Warlock: To the Magic Born (UK Edition) | Omnibus | Warlock of Gramarye |
| The Warlock Rock | Novel | Warlock of Gramarye | |
| 1991 | The Warlock Enlarged (UK Edition) | Omnibus | Warlock of Gramarye |
| The Warlock's Night Out (UK Edition) | Omnibus | Warlock of Gramarye | |
| A Company of Stars | Novel | Starship Troupers | |
| Warlock and Son | Novel | Warlock of Gramarye | |
| 1993 | A Wizard in Absentia | Novel | Rogue Wizard |
| The Oathbound Wizard | Novel | Wizard in Rhyme | |
| We Open on Venus | Novel | Starship Troupers | |
| 1994 | End Run (with William R. Forstchen) | Novel | Wing Commander |
| The Witch Doctor | Novel | Wizard in Rhyme | |
| A Slight Detour | Novel | Starship Troupers | |
| M'Lady Witch | Novel | Warlock's Heirs | |
| 1995 | The Secular Wizard | Novel | Wizard in Rhyme |
| A Wizard in Mind | Novel | Rogue Wizard | |
| Quicksilver's Knight | Novel | Warlock's Heirs | |
| The Shaman | Novel | Star Stone | |
| A Wizard in War | Novel | Rogue Wizard | |
| 1996 | The Sage | Novel | Star Stone |
| A Wizard in Peace | Novel | Rogue Wizard | |
| 1997 | My Son, the Wizard | Novel | Wizard in Rhyme |
| A Wizard in Chaos | Novel | Rogue Wizard | |
| 1998 | A Wizard in Midgard | Novel | Rogue Wizard |
| 1999 | The Spell-Bound Scholar | Novel | Warlock's Heirs |
| 2000 | The Haunted Wizard | Novel | Wizard in Rhyme |
| A Wizard and a Warlord | Novel | Rogue Wizard | |
| The Crusading Wizard | Novel | Wizard in Rhyme | |
| The Feline Wizard | Novel | Wizard in Rhyme | |
| A Wizard in the Way | Novel | Rogue Wizard | |
| 2001 | A Wizard in a Feud | Novel | Rogue Wizard |
| Here Be Monsters | Novel | Warlock's Heirs | |
| 2003 | Stolen Prophecy | Novel | Mage Knight |
| Mind Out of Time | Collection | DDT-verse | |
| 2004 | The Warlock's Last Ride | Novel | Warlock of Gramarye |
| 2005 | Saint Vidicon to the Rescue | Novel | DDT-verse |