The Underworld Player's Guide is the player companion sourcebook for Empire of the Ghouls. The OGL content includes the Class Options (excluding the Herald of the Ebon Star, the Path of the Ebon Star, and all place names and specific character references such as gods and NPCs), the Spells, and the Underworld Beasts.
Note that while the OGL declaration in this publication excludes the Herald of the Ebon Star, it has previously been explicitly declared OGL in Warlock 8.
OGL Content:
Beetle, Lantern - (monster)
Beetle, Sniffer - (monster)
Bilby - (monster)
Blood Puppet - (spell)
Boiling Blood - (spell)
Bolster Undead - (spell)
Cave Goat - (monster)
College of Echoes - (college)
Conjure Greater Spectral Dead - (spell)
Conjure Spectral Dead - (spell)
Curse of the Grave - (spell)
Dark Maw - (spell)
Dead Walking - (spell)
Death God’s Touch - (spell)
Derro - (race)
Dhampir - (race)
Disquieting Gaze - (spell)
Fennec Fox - (monster)
Ghoul Bat - (monster)
Ghoul, Darakhul - (race)
Ghoul King’s Cloak - (spell)
Giant Armadillo - (monster)
Gird the Spirit - (spell)
Gravebinding - (tradition)
Heart to Heart - (spell)
Hematomancy - (spell)
Hungering - (origin)
Hungry Spell - (metamagic)
Imperial Hunter - (ranger-archetype)
Insatiable Spell - (metamagic)
Keening Wail - (spell)
Lacerate - (spell)
Lay to Rest - (spell)
Life from Death - (spell)
Life Sense - (spell)
Lingering Spell - (metamagic)
Maw of Needles - (spell)
Not Dead Yet - (spell)
Oath of Consumption - (oath)
Rotting Corpse - (spell)
Seeping Death - (spell)
Shade - (race)
Shared Hunger Spell - (metamagic)
Soulspy - (rogue-archetype)
Spore Sorcery - (origin)
Stench of Rot - (spell)
Touch of the Unliving - (spell)
Unholy Defiance - (spell)
Unluck On That - (spell)
Way of Sated Hunger - (monastic)