How do I Add in a memory wiping or memory altering effect without explicitly stating it OOC? For example:

How do I Add in a memory wiping or memory altering effect without explicitly stating it OOC? For example:
>A magical creature that removes the existence of whatever it eats from the world. People it eats are erased from memory, history, and time.

Never allow the people who it eats to be met by the party

Have a carefully set plan of the people who are getting eaten and ensure that the party never meets them

have the party run into and save someone from being eaten

allow the party to kill the creature and for gods sake make sure none of them are eaten

if you do it right the party will never even know the creature could erase people, which is the only way to deal with an encounter with this creature

then at the end if they do find out about its true nature, drop a line about the party having 5 members

The trick I use is simply introduce the forgotten memory as new information that the player or character have never heard before.

>drop a line about the party having 5 members
Holy shit.

OK so it's a bad idea to have them be erased from history and time, because then you have to get into the whole linear time travel bullshit of causation and what should change based on the new timeline. Fuck that noise.

Instead, focus on the memory. This is Oceania, and the guy who just got devoured is now an unperson. There are records of him, but no one remembers him. Who is this man, and why is he in all our photos?

Perhaps contrasthis with a monster that hunts its humanoid prey by inserting itself into a social group and convincing them they all know it. In Bleach, the villain Tsukishima's power "Book of the End" allowed him to insert himself into people's memories in whatever way he liked: to some he was an old friend, to others a favorite cousin, to a third, a new beau, to yet a fourth a hated enemy. Mix this with something like a Red Cap, and you've got a nice duo: a monster that deletes what it eats from memory, and a monster that adds itself to memory in order to eat.

You missed a fill-in on the top portion, btw

>drop a line about the party having 5 members

if your party is special you can have only them remember it and everyone else have n clue who they are talking about

Erasing from memory and history is fine, but time is definitely the big deal. Imagine it ate a peasant, no big deal right, probably just a little bit less shit got farmed during his lifetime. But, if that peasant had say came across the just and righteous prince as a lad when he was being chased by a wolf pack and scared them away, now the prince is either dead, or scarred and probably a little crazy, either way that can affect a global change. And if it eats a party member, everytime that member did anything to advance the group's cause is now undone. If it ate the cleric, it may have just retroactively killed everyone, depending on how much healing that cleric threw around, the rogue probably got them some good gear from locked and trapped places, all gone as they either never got in, or the trap ruined it. Wizard is gone, probably another wipe situation, from where he fireballed that mass of zombies pushing in, or used mass fly to escape a crumbling tower, even the fighter/barbarian/paladin being gone forever means they lose his raw physical power and beefiness, either making them much the worse for wear coming across this thing, and god forbid whoever it ate was the reason they came after at it, or even gathered in the first place, because that changes a hell of a lot of stuff.

That's why I would cut out time, because history is just time, written down. Doing all that is fine if you're a writer on The Flash, but not if you're running a game. You eat a PC's dad and suddenly the PC no longer exists, roll a new character.

As above, erasing history and memory is fine but time is too dangerous.
Perhaps something along the lines of a duke throwing a feast on the anniversary of his appointment, and as it's the 40th anniversary the king's attending from far away. Across the 40 years the citizens have assured themselves one series of events regarding how the duke came to become a duke but once the king and his lot pop it turns out they had re-written records supporting a completely different set of circumstances, believing the originals were burned down in a great fire.

You could even have a situation where a long-time ally of the party insists they come and check out this magnificent beast a collector has sold him, and then have the ally turn to say something to the effect of, "That reminds me! I'll need you to get me a-The sound of the blacksmith's hammer rings out as he finishes your sword. He passes it to you, smiling genuinely". The quest is of course complete and the PCs feel like nothing's missing yet of the players will go through being forced to forget something so they end up chasing that loose end.

Exploring how the mind would deal with having to come up with it's own narrative to explain where they are now would create good plot hooks.

If you mention removing from time because that's a theme in your campaign then have an NPC obsessed with the creature claiming it does remove things from time, but of course only introduce this character once the players have deduced most of the details already.
The NPC is wrong, but the red herring will tie the beast back into the themes.

I'm thinking langoliers. Give the party a time-stopping power that seems to be able to go on forever, but they're limited to exploring and a few "everyone's frozen, I've got a marker" gags. Then once they've been in stopped time for a while,
>perception check

I dunno, spitballing here.

Have them come across oddly empty houses here and there. People asked about them just say something along the lines of "I don't know, it's been there all the time. I don't remember it being used at all."

>memory altering effect
Start each session with a recap that's clearly a little off.

Hard mode: pause your session if you run into the creature and the party loses a member. Resume ten minutes later with a recap that never mentions the slain character.

"It's getting dark"
Lanaria muttered these words as the path led them past another farm house before
disappearing in the dense woodwork. Aldrik nodded in agreement.
"Let's ask the locals if they can spare a place to sleep.
Even if it's on the floor, at least it has a roof."
Beulf didn't look overjoyed by the prospect of resting in a stranger's house,
but complied as his companions set for the entrance.
A short eternity passed after they knocked firmly on the door, before a young woman
with slight bags under her eyes opened and gave them a questioning look.
"Yes?"
"Good evening mylady, we are travelers upon these lands and were wondering
whether you would allow us to spend the night beneath your roof."
Aldrik flashed his most charming smile, but it was not until Beulf brought out
a hand full of silver coins that she stopped hesitating.
"We don't mean to disturb you, you seem weary of the work"
She smiled a tired smile, but waved the words aside.
"Don't worry about me. I have always managed the harvest on my own.
This year the progress is unusually slow... you wouldn't happen to have
some time on your travels? I would pay for any help."
Upon Beulfs intent stares Aldrik hurried to decline.
"Please excuse us, we need to leave first thing tomorrow morning.
Don't neighbours help each other out in these parts?
We came across some houses, but we didn't see a single soul."
"No, no one has lived there in years... decades?"
"They were in pretty good condition."
It was the first time Beulf talked that evening, and it was immediately
followed by a long, awkward silence.
"Right, I'll show you to your rooms"

"Right, I'll show you to your rooms.
There are only two more beds, but if you don't mind, the girl can sleep
next to me, the bed is pretty large"
"Who did the other two beds belong to?"
Again it was Beulf who asked the question that baffled the woman.
"They... no one, they are for guests only"
"When was the last time a guest slept in one of those exact beds?"
Without considering her feelings, he pressed on, until Lanaria inerrupted.
"That's enough. I don't think she's hiding anything"
"Even so, I'm afraid I'll also have to ask a few more questions."
Aldrik's voice came from the door, as he returned from the other room,
in his hands a stuffed doll and a child sized dress.

How about retcons? I know it's meta, but realistically meta is the only way to go about this.

By retcon, I mean if someone gets eaten, just tell the players you decided that they didn't make sense and didn't exist or something.
Or just pretend they never existed. Even if the players twig what you're doing OOC, it could represent the characters getting uneasy IC.

Also: go look up False Hydras

Reminds me of those parasites from Rick and Morty.

You mean like pic related?

>>A magical creature that removes the existence of whatever it eats from the world. People it eats are erased from memory, history, and time.

>Pull out a character sheet from under the table
>It's filled out with all the relevant information and level-appropriate gold and gear

Introduce weirdly incongrous evidence of the person's existence only after they are gone. Like, the party finds a note written to a person they know, from a person no one remembers. It seems very casual and friendly and references prior conversations, but the NPC claims they have never heard of them.

Upon checking, the NPC finds a stack of papers in their office, hidden away. Many of them are letters from the same person, like what you found but older. A few are letters with random words missing. The rest are blank pages, mixed in with the rest.

The monster erases people from memory and history, but they rarely get EVERYTHING. Its like eating toast: you miss crumbs. So some random people who only barely knew the guy still remember him like nothing happened, even when his own mother doesn't. All of his stuff is missing, but no one can explain why there is an unused bed in the house. Photos where he appears, but the people who have forgotten him can't see him in it.

Imply that the evidence of the mans existence is all still there, but people just don't see it due to the magical effect. Which implies that the man's stuff is actually still all in his room, you just can't notice it. The magic won't let you.

This might manifest as a headache that happens if you spend too long looking at something that your brain is being forced to ignore. Once you figure that out, that headache becomes your radar.

Shit, now I want to do a scenario where the villain won and remade rhe wprld through time-fuckery but the characters partially remember the old world and he tries to kill them to complete his victory.

>an entire campaign in post-Made In Heaven world