TSR, Inc. hired Nesmith in 1981 to design computer games on the Apple II+, and he soon moved on to be a writer of Dungeons & Dragons modules.

[1] After the original Dragonlance group began, the Dragonlance Series Design Team was later expanded to include Nesmith as well as Margaret Weis, Douglas Niles, Mike Breault, Roger Moore, Laura Hickman, Linda Bakk, Michael Dobson and Garry Spiegle.

[2] Nesmith designed Ravenloft: Realm of Terror (1990), which built on the ideas explored in the original Ravenloft adventure written by the Hickmans in an attempt to make Advanced Dungeons & Dragons competitive with horror role-playing games such as Call of Cthulhu and Chill.

[3] Nesmith and Andria Hayday designed the DragonStrike board game, which was published by TSR, Inc.[4] His other design work for D&D includes The War Rafts of Kron (1984), Sabre River (1984), Master Player Screen Featuring The Spindle (1985), The Book of Lairs II (1987), Tales of the Outer Planes (1988), Monstrous Compendium, Volume 2 (1989), Monstrous Compendium, Volume 1 (1989), Hall of Heroes (1989), Monstrous Compendium Spelljammer Appendix (1990), Monstrous Compendium Greyhawk Appendix (1990), Monstrous Compendium Dragonlance Appendix (1990), Greyhawk Ruins (1990), Touch of Death (1991), Monstrous Compendium Forgotten Realms Appendix II (1991), Goblins' Return (1991), Darklords (1991), Unsung Heroes (1992), From the Shadows (1992), Forbidden Lore (1992), Van Richten's Guide to Werebeasts (1993), House of Strahd (1993), The Created (1993), Ravenloft Campaign Setting, 2nd Ed.

(1994), Hour of the Knife (1994), First Quest (1994), Dark Sun Monstrous Compendium Appendix II: Terrors Beyond Tyr (1995), Psionic Artifacts of Athas (1996), and Domains of Dread (1997).