Player's Handbook
Your patron is a mysterious entity whose nature is utterly foreign to the fabric of reality. It might come from the Far Realm, the space beyond reality, or it could be one of the elder gods known only in legends. Its motives are incomprehensible to mortals, and its knowledge so immense and ancient that even the greatest libraries pale in comparison to the vast secrets it holds. The Great Old One might be unaware of your existence or entirely indifferent to you, but the secrets you have learned allow you to draw your magic from it.
Entities of this type include Ghaunadar, called That Which Lurks; Tharizdun, the Chained God; Dendar, the Night Serpent; Zargon, the Returner; Great Cthulhu; and other unfathomable beings.
The Great Old One lets you choose from an expanded list of spells when you learn a warlock spell. The following spells are added to the warlock spell list for you.
| Great Old One Expanded Spell List | |
| Spell Level | Spells |
| 1st | Dissonant Whispers, Tasha's Hideous Laughter |
| 2nd | Detect Thoughts, Phantasmal Force |
| 3rd | Clairvoyance, Sending |
| 4th | Dominate Beast, Evard's Black Tentacles |
| 5th | Dominate Person, Telekinesis |
1st-level Great Old One Feature
Starting at 1st level, your alien knowledge gives you the ability to touch the minds of other creatures. You can telepathically speak to any creature you can see within 30 feet of you. You don't need to share a language with the creature for it to understand your telepathic utterances, but the creature must be able to understand at least one language.
6th-level Great Old One Feature
At 6th level, you learn to magically ward yourself against attack and to turn an enemy's failed strike into good luck for yourself. When a creature makes an attack roll against you, you can use your reaction to impose disadvantage on that roll. If the attack misses you, your next attack roll against the creature has advantage if you make it before the end of your next turn.
Once you use this feature, you can't use it again until you finish a short or long rest.
10th-level Great Old One Feature
Starting at 10th level, your thoughts can't be read by telepathy or other means unless you allow it. You also have resistance to psychic damage, and whenever a creature deals psychic damage to you, that creature takes the same amount of damage that you do.
14th-level Great Old One Feature
At 14th level, you gain the ability to infect a humanoid's mind with the alien magic of your patron. You can use your action to touch an incapacitated humanoid. That creature is then charmed by you until a Remove Curse spell is cast on it, the charmed condition is removed from it, or you use this feature again.
You can communicate telepathically with the charmed creature as long as the two of you are on the same plane of existence.
Warlock Patrons, Boons, & Invocations version 2.1.0 by Laserllama
The Great Old One lets you choose from an expanded list of spells when you learn a warlock spell. Starting at 1st level, the spells below are added to the warlock spell list for you.
| Great Old One Expanded Spell List | |
| Spell Level | Spells |
| 1st | dissonant whispers, hideous laughter |
| 2nd | detect thoughts, levitate |
| 3rd | clairvoyance, slow |
| 4th | confusion, resilient sphere |
| 5th | dominate person, telekinesis |
1st-level Great Old One Feature
When you enter your Pact at 1st level, the hidden potential of your mind is unlocked. You can telepathically communicate with any creature you can see within 60 feet. You don’t need to share a language, but the target must speak at least one language in order to respond to you. You can only use this feature to communicate with one creature at a time.
In addition, you learn the mage hand cantrip, but it doesn't count against your total number of Cantrips Known. When you cast mage hand, you don't need to provide the verbal or somatic components, and your mage hand is invisible.
6th-level Great Old One Feature
At 6th level, you can use your psionic power to potentially deflect enemy attacks. When a creature that you can see hits you with an attack, you can use your reaction to roll a d4 and add it to your Armor Class against the triggering attack.
10th-level Great Old One Feature
Starting at 10th level, you gain resistance to psychic damage, and you have advantage on any saving throw you make to resist both the charmed and the frightened condition.
14th-level Great Old One Feature
Beginning at 14th level, you can use your action to touch an incapacitated humanoid, causing it to be charmed by you.
You can communicate telepathically with the charmed creature as long as the two of you are on the same plane of existence. You can issue the creature commands using your telepathy, which it does its best to obey. It will not follow any commands that cause itself immediate harm or death.
The creature remains charmed until a remove curse spell is used on it, the charmed condition is removed, or you use this feature to charm another creature.