# Intruder retake

## About

### What is the Intruder?

#### Blurb
The Intruder is a cosmic horror entity from another dimension. Through some unknown means, the Intruder became aware of this plane of reality. Everything is completely different to it and new. The only thing that isn't new to it is thoughts, which are everywhere, simple and complex. Wanting to merge itself further into reality, and still accustoming to the universe, it seeks to start off by possessing the station's critters.

However, the Intruder isn't alone. It's managed to bring forth some of it's invasion force with it, the Mindeaters/Invaders, to handle the more complex thoughts.

Mindeaters/Invaders are creatures that live in the Intruder plane, that are an extension of the Intruder. They represent a more hostile, more tangible will of the Intruder. They seek to consume minds rather than consume reality.

#### Themes
- Critter possession
- Mind power
- Mental draining
- Non-human entities
- Extra-dimensional horror
- Extra-dimensional invasion
- Thematic events

### Goals
- Create a game mode that is unique
- Create an antagonist that is obviously non-human but still playable
- Create a more cosmic horror themed antagonist
- Create an antagonist that has new/unique gameplay themes
- Create an antagonist with variability and good depth, but is still straightforwards

### Non-goals
- Repeat features that previous antagonists have
- Make an antagonist that is unfun to play
- Create an antagonist that doesn't need to interact with humans to perform its abilities
- Create a complicated antagonist
- Create an antagonist that snowballs

### Game mode itself
#### Goal of the antagonists
The Intruder's role is more of a distraction/support/slight offense role for its Mindeaters, who do the work of killing people.

The goal is for the Intruder and Mindeaters to consume the minds of a certain number of crew members (maybe 1/4 of starting players) in a given time span (30 minutes?). Failing to do so will result in loss for the Intruder and Mindeaters. Upon reaching the number of minds eaten, some ??? event happens

The Intruder can really do whatever, but should generally be sticking around a Mindeater, or close by creating critters.

Mindeaters are more meant to go solo, to follow and pick off, or hit and run, alone targets. They have some survivability when against groups, but don't benefit much from it. In this case, it's recommended the Intruder help out. Nothing is stopping Mindeaters from going together, but their brain drain is scaled in that case to prevent a death group patrol.

- Once Intruder reaches its goal, spawns final boss event (maybe), and shuttle is called. Regardless of whether boss is killed or not, crew loses. Station starts rapidly becoming Intruder turf.

#### Intent
- To be a full, roundstart game mode
- One Intruder
- Several mindeaters

## Intruder Mechanics

### Starting out
The Intruder starts out as an intangible entity, and will always stay intangible.

It has vision of everything of the AI.

### Stat points
The Intruder has a statpoint called Mindpower. Mindpower is awarded by Mindeaters, summoned Intruder/Mindeater critters, or Intruder turf, fully draining someone of their brain. Mindpower just shows the number of minds eaten in respect to the Intruder's end goal.

All Intruder abilities are cooldown based and do not cost anything.

### Abilities
Intruder's abilities are mainly more around assisting its Mindeaters and consuming the station and its critters.

Some abilities drain brain from people. In this case, all brain drained is awarded as a small fraction to all Mindeaters.

Using abilities also has a chance to convert a random nearby turf to Intruder turf. People who walk over it have a small amount of their Brain drained.

#### Primary abilities:
- Mass recall - Channel to bring all Mindeaters to your location.
- Summon - Channel to bring a Mindeater to your location, interrupted if they enter combat.
- Invade - Channel to invade the mind of a critter or human-like NPC (ex. monkey). NPCs take longer to possess. Possessed creatures are very obvious and hostile.
- If targeted on a turf, will instead start a longer action bar to summon a critter, randomly picked from the ones you've previously possessed.
- Command - Commands all nearby possessed critters and summons to travel to and attack anyone at the clicked location
- Eclipse - Starts on cooldown. Activate to create an Eclipse event, picked from one of three randomly selected events from the total pool. Each is only usable once. Eclipse events are major events that happen in the game with a big announcement/audio crew to everyone to signal that one has happened.
- Mark - Selects a Mindeater to cast your assistive abilities off of.

#### Assistive abilities:
All have a shared cooldown and only can be casted in range of a Mindeater that you've selected.

- Insanity (remove powerful targets from groups) - For a single target, start a brain loss debuff on them over a short period of time. For the more people they are nearby, the more it drains.
- Zap (split up groups) - Create a purple lightning arc at a spot, that jumps to targets nearby, up to a few times, with short pauses in-between each jump. Each target hit will receive brute and burn damage and disorients.
- Conflagrate (area of denial) - Create random patches of Eldritch fire in an area that gives the on-fire debuff to those who walk through it and a toxin damage over time debuff.
- Crumple (disruptive) - Channel to destroy an object with a mob inside of it, dealing a high amount of brute damage to whoever is inside if they don't leave. Can target objects like closets, pods, etc.
- Warp (evasive) - Create a temporary opening through a wall that Mindeaters and humans can pass through for a short duration.
- Short circuit (cover) - Creates patches of static in an area that all mobs cannot see through over a short duration.

#### Eclipse Events
- Blackout - All lights in a specific area and nearby go out, and are replaced with an eerie, dim, colored light instead.
- Spire event - Summon a Spire summoning event. All turfs nearby start becoming Intruder turfs, and entities from the Intruder plane summon. Starts out small and grows over time. To stop it, crew must destroy the Spire.
- Resurrection - Resurrect one of your dead Mindeaters.
- Agitation - For a number of maintenance areas, spawn critters in them if not already, and immediately possess all critters in them, making them attack the crew.
- Merge reality - Creates patches of Intruder tiles across the station.
- Spatial swap - Create patches of alternate biomes across the station (ex. desert, jungle, etc) with creatures from those biomes coming with (scorpions, monkeys, etc).
- Wellpoints - Spawn dimensional cracks around the station. People who walk nearby have Brain rapidly drained. Must be destroyed to stop them.

#### Critters
- Possessed and summoned critters are meant to be very weak cannonfodder, but can appear in swarms.
- Very obviously possessed.
- Most can die in one hit from something like a fire extinguisher
- Each attack from them deals brain damage
- Cannot use any of their previous abilities

#### Intruder turf
Intruder turfs appear through the Intruder casting an ability, or eclipse sevents.
- To be destroyed, they must be destroyed with item attacks.
- Walking over them causes brain damage to the person who does it
- Cool icon flick when walking over it

### Presence level
As the Intruder's Mindpower increases, it will reflect across the station.

Upon increasing Mindpower, any of the following can happen randomly on the station, per reaching a certain Mindpower level
- 1/5 final Mindpower
- Fog like color shifts that appear
- 2/5 final Mindpower
- Cosmic particle effects
- 3/5 final Mindpower
- Cosmic space fluids
- 4/5 final Mindpower
- Dimensional cracks
- Purple lightning crackles that arc around

### Death
- To kill the Intruder, all of it's Mindeaters must be killed.
- Intruder automatically dies at a certain time limit if it hasn't won by then

### Gameplay
- Directly assists Mindeaters and distracts the crew
- Consumes the station's turf and critters to cause distractions that pull people away from Mindeaters
- Creates events the crew must work around

## Mindeater Mechanics

### Starting out
The Mindeater starts out as an intangible entity. It can choose to become tangible anywhere it wants, once.

Immediately, it has several abilities it can select to become available.

Mindeaters have the same vision level as the Intruder.

### Unique features
- Non-human in form. Some sort of cosmic-horror.
- Cloaks when going into darkness, if not in combat. Going into light or space, after a few seconds it will decloak. Being attacked or stunned, or using certain abilities de-cloaks it and prevents it from recloaking for a bit of time.
- While visible, can be seen by the AI and cyborgs. When invisible, can't be seen by them.
- Can move through reflective objects.
- Opens doors on touch
- Full heat, cold, oxygen damage, and radiation immunity.
- Full stun immunity. Still receives disorients.
- Damaged by space (starlight of this reality harms it)
- One built in ranged attack.
- Doesn't hear radio (may change later to hear radio)
- Runic/intangible speech (cool to do custom font, but low priority)
- Can't be killed under normal means (see later)

### Stat points
The Mindeater is based around gaining Intellect from targets. Intellect has a low max cap and is used to cast some of its abilities.

### Primary attack - Mind bolt
Its primary attack is a ranged weapon that fires psychic paralysis bolts.

This is a rapid fire, spammable attack that applies a movement loss debuff and prevents you from running.

If you have chemicals in you, they will be converted into toxins.

### Abilities
#### Primary abilities
- Request assistance - Sends an assistance request to the Intruder
- Brain drain (0 intellect) - Private channel that's interrupted on attack or stun, target a living mob to gain 3 Intellect on them per second, while in range. Removes the mindeater's invisibility on use.
- Target mob receives 1 brain per second, and randomly picked brain damage, tox damage, brute damage, or burn damage each second.
- Having haloperidol, morphine, or ethanol in you reduces Intellect gained by the mindeater.
- Taking mannitol will reduce Intellect collected on you while not being brain drained.
- Below 25 Intellect, the target receives below 25% threshold messages.
- After 25 Intellect, the target starts receives a screen overlay that shows their mind is being eaten. Purple particles will start floating around them.
- After 50 Intellect, the purple particles will now float towards the Mindeater. They receive 50% threshold messages.
- After 75 Intellect, the target will start hallucinating plane merging phenomena, like Intruder turfs appearing or funky animations on random objects.
- After 100 Intellect, the person's sprite starts warping.
- A target can only be brain drained by 1 mindeater at a time
- Other
- If draining someone while they die, a Mindpower point will be awarded to the Intruder instantly.
- If targeting a Cyborg, it will damage its head.
- Doesn't work on dead targets
- Regenerate (1 intellect) - Use Intellect to heal. Can only be used out of combat.
- Project (free) - Create a fake version of yourself at a target location
- Spatial swap (free) - Swap the location of yourself and a living creature or fake version of yourself.
- Paralyze (free) - Cast is only successful on a target that's facing you, will fail with cooldown on those facing away. Reduces their vision. Makes them unable to move and take 1 step towards you and 1 stab for each 10 Intellect on them.
- Cosmic light (free) - Cast a purple glare from you that, while mobs are facing you, gain Intellect from them.
- Pierce the Veil (costs 100 Intellect) - Visible channel. Gain a 3 charge shield while channeling, if the shield is destroyed the ability ends. Charges are removed on being attacked. On end, lock a target mob that has 100 Intellect into an Intruder-fied arena for 60 seconds. Mobs inside receive constant brain damage and need to defend against critters called Mindmites that appear. If they die, the Intruder is awarded a Mindpower point.
- Disguise (free) - Appear as a random human, mouse, or cockroach

#### Side abilities
These are other abilities found at the lower right of the screen

- Toggle Psi Bolt - Toggles whether while in disguised form, clicking will fire a psi bolt or not
- Speak Toggle - Changes whether speaking will be sent internally to the Intruder and all other mindeaters, or aloud

### Death
- After dying, its allowed to come back after a certain period
- Becomes intangible on death and will become tangible again after a certain period
- To permanently kill it, need to do something specific (see section for dealing with Mindeaters)

### Gameplay
- Fast paced. Medium Intellect drain rate, with low maximum cap on what can be stored.
- Lethality through brain damage
- Powerful abilities with a purpose
- Focus is more on eating a target's mind rather than being physically lethal.
- Very non-human, but not as deadly as antags like werewolves.

## Status effects and overlays
A major intent of the game mode is to make a lot of use of "status" overlays, like how Flock uses health indicators over things.

Mindeaters and Intruders can see each other's overlays, and the overlays on humans.

Overlays
- People who have mannitol in them will show a "Brain protection" status over them
- People with Mindfluid will have a "Brain protection+" indicator
- People will show their current brain dmg level on them as a display
- People holding an item plated in Eldritch presence will have a danger icon on them
- Mindeaters will have a "Vision status" indicator on them, as well as a status effect, looking like an eye, or an eye with a slash through it, showing if they are visible to everyone or not.
- Mindeaters will have a health indicator on them, showing their current health level.
- Mindeaters will have a status effect

## Dealing with the Intruder and Mindeaters
One of the main way to deal with the Intruder and Mindeaters is to use Eldritch presence, in various ways.
- When Mindeaters fully brain drain someone, it will drop an "Eldritch presence" material (physical remnants of someone's mind the Mindeater doesn't want)
- Eldritch presence can be crafted into things (through "memory" shapeshift shenanigans), as well as be arcplated into things
- Craftables
- Eldritch chest plate - Slightly reduces brain damage received from possessed critters/summons
- Eldritch crown - Reduces brain damage received from Intruder abilities and Mindeater brain drain.
- Special plating effects
- Items - Increases their damage slightly against Mindeaters. Also allows killing blows to permanently kill a Mindeater
- Guns - Same as for items, but affects ranged attacks
- Thermal goggles - Allow you to see Mindeaters and the Intruder.
- Mindfluid
- Created by mixing mannitol and eldritch presence. Clears Mindmites disease, and counters Mindeater's Metabolic Overload

Flashlights (need to confirm if this will work)
- Flashlights will reveal Mindeaters

Mousetraps
- Invisible Mindeaters will be revealed by mousetraps

Mannitol
- Mannitol will reduce brain damage effects, and is a hard counter to the affects of the Intruder and Mindeater's abilities. However, it can be counter-acted by Mindeater's Metabolic Overload ability.
- Mindfluid is an improved alternative

Brain damage
- Having 60 brain damage in you will allow you to see Mindeaters, which is risky but works.

Awareness
- Intruder and Mindeater abilities are less physically lethal, and more mentally lethal, being less dangerous in a specific sense. Intruder abilities have a clear indication of when they're happening. Awareness of their effects will help determine if something is happening to you from them.

## Required reworks/revamps/etc
### Critter spawns
Before Intruder is fully added, it should be made so that all maintenance areas will spawn critters to maintain at least a certain number of critters in them

Also, it would maybe be cool to add more varieties of critters that can appear, such as rats and spiders

### Brain damage
Possibly tie brain damage to brain organ, instead of mobs? Would allow cyborgs to receive brain damage.

### Critter possession mechanics
Need to make it so only weaker, biological critters without player minds can be possessed by the Intruder. Ex. cockroaches, mice, but not things like cleanbots.

## Possible Issues
- Boring for Intruder
- Unlikeable. Initial ability/gearset is very different from most other mobs, and it might force players into a playstyle that is unfun or that they don't want.
- Not friendly to newer players. Playstyle is very different from most other mobs/antagonists in the game. More based on stealth, and you can't disguise yourself among crewmates. On the other hand, you don't have to opt into the antagonist if you don't want to play it.
- Mindeaters may not be lethal enough

## Development related
### Help needed
- Codewise, should generally be pretty straightforwards
- Likely need help with spriting and sound.

### Stuff to remember to code (internal)
- Prevent Mindeaters from going into pods
- Remove sprint puffs, it's a mob property or something like that
- Mindfluid desc - "A concoction of mannitol and some lost memories. Pseudo-science, or a miracle?"
- End game report - Show minds eaten, and deaths received, of each Mindeater
- Intruder/Mindeater fire colorable per player choice
- TV-static like effect gib
- Mindeaters are differentiated by fire color
- Purple lightning shaped crackle particles around possessed critters

### Deprecated ideas
- Convert turf ability for Intruder

- Intruder abilities
- Increase mind power - Slightly increase a Mindeater's brain drain rate for a short duration.
- ??? - Reduce a Mindeater's current cooldowns
- Darken (MAYBE) - Darken the lights near where you click for a short moment.
- Amplify - Temporarily increase a Mindeater's movement speed
- Empower - Buff critters in a selected area, increasing their hp and brain dmg attack for a short duration.
- Incentivize - Increase critter spawn rate for the target area.
- Tunnel - Start an action bar to pull a Mindeater to yourself, as long as it hasn't been in combat for a period of time.
- Mass recall - Channel to bring all Mindeaters to your location.
- Summon - Channel to bring a Mindeater to your location, interrupted if they enter combat.

- Structures for Intruder
- Summon structure - Summons a structure of your choosing at your location. Placement is instant. All structures are invisible for a short duration, and slowly become more visible over time.
- Warper - Warps space around it
- [light source] of [emotion]
- Ex. Candle of Woe, Light of Memories ("Looking into this light, you remember your childhood. You shudder from the unnatural feeling.")
- Looks like a pedestal holding a fire above it
- Creates a light source around it, darkness past that
- Inverter - Allows Mindeaters to cloak on nearby turf, even if in light.
- Pacifier - Structure that prevents nearby mobs from attacking Mindeaters.

- Eclipse events
- Summon an Intruder plane Harbinger, a large 3x3 or 5x5 mob that converts turfs it moves over to Intruder turfs. Hostile and drains brain from nearby targets.

- Claw hand attack for Mindeaters - One or two claw hands that do low damage, but cause disorient/stun on targets, doing more the more brain damage a target has.

- Mindeater abilities
- Offensive (pick one):
- Crumple - Deal brute damage to a target proportional to the brain damage they have.
- Intrude mind - Create a critter swarm for a target that only that player can see. In otherwords, hallucinations that actually kill the person.
- Psi bolt - Fire a psychic bolt that when hitting someone, deals toxin damage and causes a player slowness. Neurodepressant maybe?
- Telekinesis - Steal several objects from a target location and from people's hands, making them hover around you for a short duration.

- Defensive (pick one):
- Pacify - Prevent a target from using melee attacks or guns for a short time.
- Share minds - For a short time, melee damage and ranged damage you take is dealt fractionally to nearby people.
- Diffuse - Block the next melee/ranged attack on you.
- Confuse - Cause the target's melee range attacks to be swapped between the Mindeater and themselves for a short time. Meaning the target's attacks will hit themselves if targeting the Mindeater, and they will hit the Mindeater if targeting themselves.
- Emergency - Summon creatures from the Intruder plane to assist you, which have timed life. They will only stay in the area you spawned them in.
- Create - Right click to select a manifestation type. Left click tile to place it, has timed life, or disappears when attacked.
- Options:
- Group of possessed critters
- Fire
- Mindeater
- Patch of Eldritch turf

- Evasive (pick one):
- Meld - For everyone nearby, make their vision look greyscale, and everyone look like the same person, along with yourself.
- Shades - Create several versions of yourself in a pattern around you. They move with you. Hitting them makes them disappear, but also deals minor damage to you. Once all disappear or after a small period of time, it ends and goes on cooldown. Casting the ability again during this period will end it immediately.

- Ultimate (pick one):
- Invade - Eldritch zombify a fully braindead target. Becomes an AI monster that attacks people for brain damage and toxin.
- Bloom - Convert nearby turf to Intruder turf, gain increased damage resistance, and passive brain drain from nearby mobs for a medium duration
- Abduct - Take a target's mind to an intruder plane. Consumes brain while they are there, maze to escape with evil creatures. Has limited time to escape. If they don't escape, their body dies in the SS13 plane. Can't be brain drained during this period.