Stealth System

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  STEALTH MOD
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A vanilla+ stealth experience for Fabric 1.21.1

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OVERVIEW
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Stealth Mod adds a fully server-authoritative detection system
to Minecraft that gives hostile mobs the ability to hear and
see you before they decide to chase. Instead of instantly
locking onto the player the moment they enter range, mobs now
go through graduated awareness states — giving skilled players
the opportunity to avoid combat entirely, reposition, or plan
their approach.

This is a vanilla+ mod. Normal Minecraft combat mechanics are
completely unchanged. If you prefer to fight mobs head-on you
can ignore the stealth system entirely and play exactly as you
always have. The stealth mechanics reward players who choose
to engage with them.

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HOW DETECTION WORKS
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Every hostile mob tracks an internal detection value (0–100)
for each nearby player. That value rises when the mob sees or
hears you, and decays back to zero when you break line-of-sight
and stay quiet.

Detection States
  UNAWARE     (0–39)   — Mob has no idea you are there.
  SUSPICIOUS  (40–79)  — Mob heard or briefly glimpsed you.
                          It will investigate the last known
                          position and search the area.
  HIGH ALERT  (80–99)  — Mob is actively looking for you.
                          Movement speed increases.
  CHASING     (100)    — Mob has fully detected you and will
                          pursue using vanilla chase AI.

Disengage
  Once a mob is CHASING, it will continue pursuing until you
  break line-of-sight AND move beyond 40 blocks for at least
  4 seconds. After that, detection drops back into HIGH ALERT
  and begins decaying normally. A full drop from 99 to 0 takes
  approximately 10 seconds with no new stimuli.

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VISION DETECTION
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Mobs perform a line-of-sight check toward the player each
tick when within detection range.

  Day range   — 20 blocks
  Night range — 12 blocks

Factors that reduce how quickly a mob spots you:
  - Sneaking (crouch) significantly reduces vision gain.
  - Standing in tall grass or other concealing plants provides
    a concealment bonus.
  - The Camouflage enchantment on your chestplate further
    reduces vision detection gain.

If a mob achieves line-of-sight within 3 blocks, detection
immediately jumps to CHASING — there is no hiding at
point-blank range.

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SOUND DETECTION
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Actions you take generate sound stimuli that nearby mobs can
hear (up to 16 blocks). The louder the action, the more
detection is added per tick a mob hears it.

Action                 Relative Loudness
  Walking              Low
  Jumping / Landing    Medium
  Sprinting            High
  Opening a Door       High
  Opening a Chest      High
  Breaking a Block     Very High
  Placing a Block      Very High
  Melee Combat         Very High
  Firing a Projectile  Medium-High

Ways to reduce sound detection:
  - Sneaking (crouch) reduces all sound output by ~33%.
  - Walking on wool blocks or carpets completely silences
    footstep sounds (walk, sprint, jump, land).
  - The Silent Step enchantment on boots reduces sneaking
    sound output further (three tiers).
  - The Muffled status effect provides an additional large
    sound reduction on top of any enchantments.

Vibration particles travel from the sound source to the mob
when a sound stimulus is accepted. These will not appear
once a mob is already CHASING you.

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MOB BEHAVIOUR
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Investigation
  When a mob reaches SUSPICIOUS or HIGH ALERT it will path
  toward the last position where it saw or heard you. If it
  reaches that spot without finding you it begins a timed
  local search, wandering the area for several seconds before
  giving up and letting detection decay.

Alert Sharing
  When a mob's detection crosses a major threshold (SUSPICIOUS,
  HIGH ALERT, or CHASING) it broadcasts an alert to all other
  eligible hostile mobs within 12 blocks. Those mobs are
  raised to at least SUSPICIOUS — they will not be
  forcibly put into CHASING by a shared alert alone.

Difficulty Speed Bonus
  Mobs move faster depending on world difficulty once they
  begin investigating or chasing.
    Easy      +20% movement speed
    Normal    +25% movement speed
    Hard      +33% movement speed
    Hardcore  +33% movement speed

Close Combat Trigger
  Striking a mob within 25 blocks while not concealed by
  grass immediately triggers CHASING, regardless of prior
  detection value.

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HUD
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A small indicator appears on screen while you are sneaking,
showing the highest detection value any nearby mob currently
has on you.

  [  -  ]  white   — Unaware or low detection
  [  ?  ]  green   — Suspicious (40+)
  [  !?  ]  amber  — High Alert (75+)
  [ !!! ]  red     — Chasing (95+)

A subtle dark vignette also appears around the screen edges
while you are crouching to reinforce the stealth state
visually.

Above-Head Mob Labels
  When a mob's detection of you reaches SUSPICIOUS or higher
  a floating indicator appears above its head (visible to
  the player it is tracking):

    ?    (green)  — Suspicious
    !?   (amber)  — High Alert
    !!!  (red)    — Chasing

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ENCHANTMENTS
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Silent Step (Boots)
  Reduces sound output while sneaking.
    Level 1 — 45% sound reduction
    Level 2 — 55% sound reduction
    Level 3 — 75% sound reduction

Camouflage (Chestplate)
  Reduces the rate at which hostile mobs accumulate vision
  detection against the wearer.

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STATUS EFFECTS
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Muffled
  Adds a large bonus (50%) to sound reduction on top of any
  existing sneak or enchantment reductions. Useful for
  missions where near-silence is required.

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COMPATIBILITY & REQUIREMENTS
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  Loader    — Fabric
  Version   — Minecraft 1.21.1
  Requires  — Fabric API

Server-side authoritative — all detection logic runs on the
server. The client only receives the detection values for HUD
display. The mod must be installed on both client and server
for the full experience; installing it only on the server
will still function but the HUD and mob labels will not appear.

No vanilla game mechanics are removed or replaced. Hostile
mobs revert to standard Minecraft targeting if the stealth
system determines that vanilla behavior should apply (e.g.,
the player is in creative or spectator mode).

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