Suleiman has made contributions to books for role-playing games such as Dungeons & Dragons and World of Darkness.
[3] Suleiman was one of the writers of Vampire: The Requiem and conceived and developed the Mummy: The Curse line.
[4][5] His D&D work includes City of Stormreach, Cityscape, Dragonmarked, Heroes of Horror, and Faiths of Eberron.
Suleiman created and developed a Cthulhu Mythos game and setting called Unspeakable: Sigil & Sign,[9] which focuses on the Old One cultists as protagonists.
Suleiman is the founder of the Washington, D.C.–based interstitial rock group Toll Carom.