- Up Against It (as M. J. Locke) (Tor Books hc, Mar 2011; Tor Books pb, Jan 2012)
- Burning the Ice (Tor Books hc, Aug 2002)
- Proxies (Tor Books hc, Sep 1998; pb Oct 1999).
- Greenwar, in collaboration with Steven Gould (Forge Books hc, Jun 1997; Tor Books pb, Nov 1998).
- Glass Houses (Analog Magazine, Dec 1991; Tor Books pb, May 1992).
- Astropilots (USA: OMNI/Scholastic pb, Jun 1987; UK: Dragon Books pb, 1987; Japan: Hayakawa Books pb, 1989).
- “True North” (as M. J. Locke) (Welcome to the Greenhouse, ed. Gordon van Gelder, O/R Books, 2011; After the End, ed. Paula Guran, Prime Books, 2013).
- “At Tide’s Turning” (Asimov’s, April 2001; Worldmakers, ed. Gardner Dozois, St. Martin’s Press, Dec 2001).
- “A Dose of Reality” (Wild Cards XIV, Baen Books pb; Mar 1994).
- “The Lamia’s Tale” (Wild Cards XIII, Baen Books pb; Mar 1993).
- “Writing on the Edges: The Science in Science Fiction” (The SFWA Bulletin, Jun 1999).
- “A Pilgrim’s Progress: My Experiments with a New Interactive Storytelling Technology” (The SFWA Bulletin, May 1997).