- To The Lord of the Rings. Ainz gives Albedo a guild ring originally intended for guild members only. Since Albedo is madly in love with Ainz, her reaction is rather more extreme than normal.Albedo: "My, my precious!"
- In one episode of the anime, Ainz casts a spell that summons a "Shark Cyclone".
- Volume 8, chapter 1. Kahjili of the goblin troops says this to Nifrea concerning his crush on Enri Neumot.
- The mechanics of Yggdrasil are heavily based on Dungeons & Dragons, specifically editions 3.0 and 3.5, and even include material from obscure Sourcebooks:
- Many spells, including Fly, Create Undead and even Floating Disk are identical in name, effect and level to spells from D&D, while others are slightly renamed but still have clear counterparts (Wall of Bones -> Wall of Skeleton, Tenser's Transformation -> Perfect Warrior). Many metamagic feats like Twin, Maximize, Widen and Silent exist as well. Super-Tier Spells are a direct counterpart to Epic Spells, and likewise Epic Spells have a limited number of daily uses even while using the variant rule that bases spellcasting on a Mana pool.
- While the monsters don't overlap completely, they tend to follow D&D logic. "Negative energy" exists as an explanation for Revive Kills Zombie, skeletal creatures are resistant to non-bludgeoning weapons, and dragons come in multiple colors with the same elemental Breath Weapons they have in D&D.
- The Wise King of the Forest is a possible reference to an infamous Spelljammer monster: the Giant Space Hamster.
- Neuronist Painkiller is a Cthulhumanoid of the "Brain Eater" race, a clear reference to D&D's Mind Flayers. Tabula Smaragdina, who appears to have chosen the same race for his avatar, is said to be a hardcore Tabletop RPG enthusiast.
- On a similar note, Punitto Moe is a humanoid composed of vines, similar to the famous Shambling Mounds.
- Albedo is described as both an imp and a succubus, but has black feathered wings rather than the typical bat wings, and occasionally shows a glimpse of her true demonic form which Shalltear describes as a "wide-mouthed gorilla". This strongly suggests that her true form is a Nalfeshnee, a type of demon which the 3rd Edition Monster Manual displayed in a group illustration alongside the imp and succubus◊. Given that her creator is the aforementioned Tabula, this is potentially an in-universe D&D reference.
- The described abilities of Shalltear Bloodfallen's "Blood Drinker" class (a blood pool which can be expended to increase the power of her spells or drive her into a frenzy) are identical to the vampire-only "Life Drinker" Prestige Class from Book of Vile Darkness, and her "True Vampire" race appears to grant similar abilities to the "Vampire Lord" template.
- In a Prequel story included with the Blu-Rays, Nishiki Enrai surprises his teammates by mentioning that the monster "Grenbera Purple Worm" uses vibrations to navigate, making it difficult to sneak past, but that he is still capable of performing a Back Stab on it consistently. This is an accurate description of the Purple Worm's Tremorsense ability, which cannot be hidden from without the Darkstalker feat (which, while extremely popular among rogue players, comes from an obscure source).
- Even the tactics used by characters in-series mirror those of experienced D&D players. Adventurers carry "alchemical silver" to pour on their weapons for fighting enemies only vulnerable to silver weapons.note Ainz has great familiarity with "Scry and Die" tactics and their counters note , and notes that it's almost impossible to defeat a high-level spellcaster unless you have a way to defend against the Time Stop spell. Almost everyone in Nazerick is either undead or wears a Ring of Sustenance to remove the need for sleep and food.note
- The author has even stated in an interview that the reason he began writing Overlord was due to not being able to play Tabletop RPG anymore with his old group of friends.
- The Great Tomb of Nazarick has the Pleiades being led by Sebas Tian, a butler with intense combat training. Almost as if the author wanted an Expy of Sebastian Michaelis. Given that he was created and named by a player of Yggdrasil, this may be an in-universe reference as well.
- Takemikazuchi had a cape as equipment which he called "Spawn Cape" and it's explicitly said it is based on the Comic Book Spawn.
- An antagonist necromancer and member of Zuranon is Khajiit Dale Badantel.
- The dub of season 1 episode 7 has Ains consider naming the giant hamster he just captured Hamtaro.
Shout Out / Overlord (2012)