100 Effects From Looking Upon A Great Old One

The Great Old Ones are a group of unique, malignant beings of immense power. They reside in various locations (buried beneath mountains, sleeping under the sea, etc.), and once presided over the planet as gods and rulers. Looking upon such a being can twist and distort the fragile minds of the mortals. Use this table to generate what exactly happens when you look upon a Great Old One.

1You see death everywhere. All around you, everything is decaying and rotting.
2You believe the people around you are slowly being replaced by dangerous imposters.
3When you have failed your death saving throws, you can decide to explode in a 100-meter radius, damaging anyone in its radius that you want it to. Those that fail the DC 30 Dexterity saving throw take as much damage as you had maximum health. You then die and cannot be resurrected except by means of a wish spell.
4You suddenly become permanently unnaturally cold.
5You are convinced an internal organ is missing. The only way to be sure, of course, is to cut yourself open and look inside...
6You slowly gain many of the superficial effects of Vampirism - paleness, sunlight sensitivity, bloodthirst - and if killed within 1d6 days of viewing the Old One rise as a vampire spawn (or vampire if you have 14 or more Hit Dice) in its service. After the 1d6 days pass the effects fade out slowly again.
7Hate overwhelms you! you immediately make an attack against the nearest creature, no matter how foolish that course would be.
8You now age backwards.
9You grow eyes on the backs of your hands, and your eyes on your head disappear. You have disadvantage on perception checks that involve sight while holding anything.
10Your hands become rotten and petrified. Nothing can heal them. No magic known to man can heal them.
11A sudden, pounding headache. Like something is trying to smash its way out of your head. Sometimes you really want to cut your head open to let it out.
12They glance back at you with flat eyes of glass like black, then move on. To beings of such immensity you - your quest, your people, your entire WORLD - are of no more importance than that which you grant to the ant you brush from your spot beside the campfire at night.
13Animals become hostile and attack upon seeing you, even if trained.
14Your legs flicker in and out of this plane. As a free action, once per turn you can choose to increase your movement speed by 30 feet. Within this 30 feet, you can walk through objects and walls. If you choose to use this ability, at the end of your turn, roll 3d6. If the total is 3, the PC is warped to a plane of the DM's choosing.
15You can no longer solve math or logic puzzles. Whenever you attempt one, for the duration that you're attempting it, it ceases to have an actual solution at all, and nobody else can solve it either.
16Time flows in strange and mysterious ways around you. You gain the benefits of a long rest on a short rest but get exhausted twice as quickly. On every short rest you complete, roll 2d20. If the result is 2, you are put at 5 levels of exhaustion and 1 HP.
17You are little more than cosmic vermin; your insights have shown you this truth. And with this realization you have gained a kinship with the vermin-kind of your pathetic little bubble of existence. Rats, Spiders, Insects and all manner of Vermin are drawn to your presence; perhaps even seeming to follow your whims and wills at times.
18You shall hunger for flesh. Once per day, you will need to make a CON Saving Throw or the urge will be extreme, and you will try to eat pieces of your friends.
19Without knowing how you know them, you begin blurting out the darkest secrets of those you meet.
20You feel something form inside you. Until you have a Greater Restoration and Remove Curse cast upon you in conjunction, any healing you take is halved as your passengers feed on your excess life. Whenever the stolen healing reaches 5 HP, a wriggling insect burrows its way out of your flesh. You take an irreducible 1d10 magical piercing damage. It flies away and causes strife as a Stirge would, staying near you and injuring or killing indiscriminately. The Queen of them lives in your center and must be cut out during your cleansing Greater Restoration and Remove Curse ritual - this deals 4d10+8 damage to you as she has lodged herself close to your heart.
21You hear your own voice telling you the dark secrets of others and encouraging you to cleanse them from this world.
22Your eyes permanently close, and you enter a trance where all you can see is an endless alien landscape.
23Every staircase you encounter will always lead down, both ways. Sometimes they lead to rooms that were not there before.
24When you look someone or something in the eyes, you can feel the gaze of the Great Old One looking back at you, always watching you.
25You feel your consciousness expanding to protect you. Your AC is now 12 + Intelligence Modifier + Wisdom Modifier, however, you can no longer wear armor to increase your AC. When you are hit by any attack, you have to roll a DC 5 Intelligence saving throw which increases by 1 every time you roll this until you take a long rest. If you fail, your AC is reduced to 10 and you are incapacitated for X/3 turns rounded up where X is the difference between the DC of the roll and your roll.
26Your mind enters a fugue state, crafting an entirely separate personality for your character if only to protect you from the trauma of glancing upon such eldritch beings.
27Your eyes gain several more pupils. They now swivel about randomly, your original eye showing the world as it originally appeared, while the others show bleak and maddening landscapes of the Great Old One's designs. While these other eyes are active, take 1d4 wisdom damage and a DC 17 wisdom check to avoid collapsing into a babbling heap.
28You experience no feelings. No joy, no happiness, nothing. Except when you see, hear, perpetrate or experience acts of violence.
29Forbidden knowledge courses through your brain. Make a wisdom save: on a success, you gain +2 intelligence and a piece of knowledge chosen by the DM. On a failure, you gain an indefinite madness.
30You don't have a precise number of fingers anymore. If you try to count them, they'll shift around, like an M.C. Escher drawing. Sometimes it seems like six or seven, other times it's just one long finger, weaving back and forth. They like to squirm and loop around each other without your control.
31Every time you close your eyes you will move closer to the sunken city of R'lyeh depending upon how long your eyes are closed for. This curse will continue even after your death.
32Your age is randomly determined each day (1d100 or other roll).
33Your blood is now ink.
34The blood within your veins changes fundamentally. You lose your minor race traits and replace them with another race’s minor traits.
35Your eyes, as well as your eyelids, are now upside down. Things look upside down to you for a few weeks, and you have disadvantage on dexterity saves, but you'll adjust after that.
36Your shadow grows enormous, as if you are always cast at twilight.
37Your mind shall grow fragile and sensitive. You gain +2 wisdom, but all psychic damage you take is doubled.
38You hear constant hissing whispers. Usually, you can't make out what they are saying, but when you do they are very dark thoughts. Sometimes you believe they are the thoughts of those around you, sometimes the dark thoughts of the living universe.
39Your flesh shall boil and pop and fall away from your body for as long as you gaze upon them, taking 2d6 damage +1d6 for every additional second you stare at them.
40Your blood begins to boil; take 2d6 fire damage and 2d6 acid damage for every turn you take even a glance at it. If reduced to 0 HP in this way your body is destroyed as Disintegration.
41Gravity always affects you only in the direction that you are looking. You have to look at the ground in order to keep from flying forwards.
42You become a conduit for a portal accessible by the great old ones.
43You leave no mark upon the world. Food you eat appears to remain untouched on the plate, footprints are no longer left behind, if you defecate there is no stool. You have no fingerprints and you cannot taste or smell anymore. Your hearing becomes faint. Your eyes, however, always see the Old One as it was when you first saw it - big as the world, behind all else you see.. save that it is looking directly at you now. You may open doors and interact with objects, you may strike others but mechanically others track and detect you at disadvantage and you make your own perception checks at disadvantage. Situationally you may offend or unnerve others, granting disadvantage in social settings for being a living Ghost. You still must go through the motions to eat, breathe, and drink - you merely appear not to have done those things after you try.
44Your mind now becomes a seed for a child of the Great Old One. You will lose control of your body and be banished from your mind eventually. In the future, the child will mature and burst from your husk.
45Your eyes shall go blind to everything but the horrendous Eldritch creatures that actually surround us, lurking just outside of our vision.
46You instinctively rip your eyes out to spare yourself from madness. Now your sight is being connected to your severed eyes but they need to be kept in a saline solution and fed like a goldfish in a jar to be used.
47Your blood begins to boil; take 2d6 fire damage and 1d6 additional damage for every turn you take even a glance at it. If reduced to 0 HP in this way your body is destroyed as Disintegration. Every time you sleep you will remember the pain and must make a will save or take 1d6 psychic damage and lose the effects of a long rest.
48Small invisible bugs start crawling all over you and biting your body, causing blisters and rashes.
49You will begin to suspect that your limbs are not your own. Once per day for 1d6 rounds, the DM may use your hands or legs for acts of chaotic nature (be it chaotic good, neutral or evil, is left to their discretion).
50Any parts of your body that regularly touch begin growing a thin piece of skin joining them. Webbed fingers and toes. Mouth sealing shut. To look normal you'll need to be constantly cutting skin off, leaving you bloody and in constant pain.
51You can now taste everything you touch.
52Every time you close your eyes and upon opening them you find yourself having moved In the direction of the old one. Slower than walking pace. But it's impossible to stop.
53Your soul leaves your body behind, yet you walk and think, not knowing you have no soul. You are considered undead.
54You will learn three new languages: one being that of the eldritch tongue, and the others randomly selected. You shall also lose knowledge of any other language you could speak.
55You gain enlightenment in the laws of time. You no longer age.
56Your bones shall grow dense and heavy. You gain the effects of medium armor, but your dexterity is halved.
57Your emotions begin to manifest into separate entities from yourself, only pure emotions manifest. You are left emotionless and your emotions with a similar intelligence running around as caricatures of yourself.
58Every time someone speaks your name you instead hear the dreadful voice of the Old One calling to you. You may change your name to a new alias, but over time the voice will slowly take that name from you as well. Mechanically you must make a save vs Fear effects at the sound of your own name, with an alias providing you only a (secretly determined by the DM) 1d6 days of solace. Anyone who speaks any of your old names to you still prompts this save. Hearing your name directed at another person (two Allison’s? No way!) merely causes you to hear the voices like a distant bell ringing, if a bell could try to listen for you.
59Your skin takes on the characteristics of random material.
60The gaze of the Old One has enlightened you to the truths of the universe, but this puts a strain on your mind. Gain double advantage on all History checks, but take [level]d4 psychic damage each time you roll a 1.
61You swap all of your memories with those of the person standing nearest to you. Not your personality, desires, or bodies; just memories.
62The sound of war drums fills your head at all times.
63The Great Old One has marked you. You gain an unconcealable, glowing mark that thrums in excitement whenever you are near an eldritch deity or eldritch energy sources.
64You change gender. Everyone else in the world remembers you as having always been that gender.
65You struggle to form new memories. Every time you wake up you must make an intelligence check or else you forget everything that happened within the past 24 hours.
66If you close both eyes, you have the sensation of being slowly devoured by rats.
67The connection between your eyes and brain gets tampered with as everything in the material plane now seems to look as if the far realm has left its mark.
68You shall hunger for your own flesh, you will need to make a CON Saving Throw once per day or attempt or cannibalize yourself for 3d4 damage.
69Everyone you see is missing a sensory part of their head; eyes, nose, mouth, or ears. They cannot sense you with the portion they are missing, and you cannot hear them if their mouth is missing. This effect lasts for 1d4 weeks.
70A terrible secret is revealed to you. A direct ancestor of yours, one Obed Marsh, discovered and mated with the Deep Ones. Only now do you feel Dagon's bloodline morphing you into an amphibious abomination with the single desire to rejoin your family.
71Whenever you fall asleep, you shall start screaming until you wake.
72You start to mutilate yourself by scratching your skin until it bleeds.
73Your sleep is forever plagued with nightmares.
74You can breathe underwater, but if you spend more than 1d6 minutes doing so, you can no longer breathe air.
75Your skin becomes covered in a thick sheet of putrid slime. Grappling you becomes harder, but grappling others is also hard (disadvantage on grappling from/against PC).
76Your brain gets covered in eldritch writing. You gain the telekinesis and telepathic feats, as well as the ability to cast detect thoughts at will. Intelligence is your spell casting ability for them. However you become vulnerable to psychic damage, and if any creature succeeds their saving throw against you, you take 2d4 damage + any spent hit dice psychic feedback damage.
77Your legs twist and contort, growing an uneven amount of new joints. You gain +20 ft movement speed, as well as a swimming and climbing speed equal to your walking, and you can jump as far as your walking speed from a standing leap. However if you move during combat you must move your full speed, failing to do so will throw you prone, for 1d4+1 rounds, and all physical damage you take will be doubled.
78Your ears get covered in thousands of holes. You understand all languages you hear, but take 1 damage for each word you hear in a language you don't know.
79Your mouth fills with several tongues, twisting and twirling out of control. Each long rest you take causes your languages to randomize.
80Your eye(s) absorb all light, and leak a vicious black fluid of the same color. You gain 60 foot truesight, but beyond that you always see the Astral plane and are considered blind.
81You hear a million voices in your head whispering for you to join them. You are hypnotized by the voice and are under the effects of the Suggestion spell. You must try everything you can to reach and touch the source of the spell. This effect cannot be counterspelled or dispelled via normal means.
82You feel like bugs are crawling under your skin and have the sudden feeling of eyes peering on you from beyond the weave. You now make perception checks at disadvantage for 1d4 hours and cannot stop trembling.
83You begin to smell smoke at first. Then the smell of cooking flesh. You look down to see your skin crackling and burning all over your body. You take 6d6+6 fire damage and 1d6 fire damage each round for 1d4 rounds. Or until you put the flames out.
84You begin to taste puke in your mouth. You have the uncontrollable urge to vomit. You puke for 1d4+1 rounds. Con. save 12 for half.
85Your eyes begin to bleed and you are blinded until a restoration spell is cast on you.
86Overwhelmed by the experience, the character blacks out, and loses 24 hours of memory in the process. Regardless of player intentions, any attempt to make the character (through mundane or magical means) remember the missing time will be actively resisted.
87The character learns a secret of the cosmos in the strange folds and geometries of the Old One. The player picks one non-combat skill; if they try to use the skill the "normal" way they roll with disadvantage, since they need to force themselves to do it "wrong", but they can roll with advantage instead, taking advantage of their new knowledge... but all observers will see their work as the product of a madman, since it flies in the face of commonly accepted principles.
88At the moment of truth, the character sneezes, and in turn does not see the full scope of the Old One. They are left with the impression that their god intervened... but also the impression that in the end, their god won't be able to save them from whatever grim fate they dodged this time.
89The character suffers a form of temporary ego death, as their psyche decides that right now it would be easier to be a rock than a person. The character behaves as though subjected to petrification, though still suffers harm as though normal flesh, and will continue to act this way until they suffer enough exhaustion levels from failing to sleep or eat to physically black out. On waking up, they can make a will save; on success, they behave as normal, on failure, they return to whatever posture they had on seeing the Old One and stop moving again. This continues until they pass the save or die.
90The character, not understanding the full ramifications of what they're seeing, suffers no consequences. Ignorance, it seems, is still the best armor against the things that linger on the edges of reality.
91You see/sense all planes of existence simultaneously, overlapped atop each other, however only interact with your current plane.
92Your feet crack and bleed, turning into roots and plunging into the ground. Your arms turn into branches. The roots and branches grow toward your core until you are a frozen tree with a head. Unable to move, you exist as a tree, staring at the great old one for eons and eternities. All that time was just a moment, as the great old one experiences it. It takes thousands of moments before the great old one moves away. In that time, you’ve existed for uncountable eternities, unmoving.
93All writing you perceive becomes a rambling, incoherent babbling to your eyes which reminds you of what you have seen. When reading any written text (Spellbooks, scrolls, street signs, etc), you must pass a Wisdom/Willpower save or fall prone and unresponsive for a number (Random, DM/GM allotted) of minutes. You can re-attempt the save if subjected to pain.
94Food has no flavor to you, slowly destroying your willpower and sanity. Alcohol and drugs offer minor, and diminishing escapes but they too start to fail you. Before long, you have forgotten what fresh bread tastes like and ale is nothing but fluid in a joyless stomach that will never know comfort again.
95Life is the great lie that saves us all from true oblivion! You see this now. You become fixated on spreading and increasing the bounty of living things - be it having numerous children, adopting and breeding animals in uncontrollable numbers or tending a patch of land that Mother Nature has been allowed to run rampant with. Anything to keep the lie going; regardless of what it costs you or how people perceive you. Anything to keep the whispers of those from outside reaching you at night.
96Over a period of 1d20 days, you become increasingly convinced that you have laid eyes on a God, no, THE one GOD, and that HE is calling you. You are convinced that HE resides in the depth of the sea. You will also constantly preach of HIS greatness. While afflicted, each time you come within 2d20 meters of a body of water (any exposed body of water/liquid containing water, be it a mug of ale, a septic tank, a puddle, a lake, river or the sea) you have to pass an intelligence and a willpower test. If you fail either or both, you will attempt with all your physical strength and cunning to submerge yourself in said body of water/liquid to be closer to HIM. If the body of water/liquid is large enough and no one stops you, you will drown. Your party needs to physically subdue you or render you unconscious and move you outside the 2d20 range of influence to stop you from trying. Healing can be attempted only after the 1d20 days are over, and a healer needs to pass three consecutive intelligence tests to free you of the affliction. The healing can be attempted twice a day.
97A strange miasma surrounds you, and it seems that whenever you hold or carry something for long enough, they'll start to gain eldritch properties. Holding onto them for even longer and your possessions will eventually mutate into sentient eldritch monsters.
98Your face vanishes from your head, rendering you unable to speak, see, smell, or even breathe.
99You now have a perfect recollection of your dreams, and can lucid dream at will.
100You begin to devolve, stage to stage, before turning back into primordial ooze.