Eco-System System Design

Version 21.2 by Alexandros Mloukie on 2025/12/19 21:43

0 - Introduction

This documentation describes a system that establishes a framework for creatures' behaviours within the ecosystem. This system aims for consistency, enabling the player to understand and explore more of the organic variations and predict the location or behaviour of the creatures.

0.1 - Disclaimer

In this document, the names and examples used are for illustrative purposes only; they are not creatures or anything else that are designed for this game. This is a living document, and any specifics pertaining to the mechanics, numbers, and more are subject to change. The assignee of this task is free to apply any values, effects, and other unspecified elements, or contact @Adam Janus  or @Utku Dagli to get further guidelines.

0.2 - Terminology

TermMeaning
PCPlayer Character
NPC

Non-Playable Character

Micro-ZoneInvisible spawn region, within a biome tied to terrain function
State MachineA system for managing the creature's behaviour through states
Behavioural StateCurrent behavioural state of the creature

1 - System Architecture

This system operates on four interconnected layers. Each layer builds upon the previous layer.

  • Layer 1: Creature State Machine
  • Layer 2: Micro-Zoning
  • Layer 3: Interaction Chains
  • Layer 4: Environmental Traces

System Architecture

1.1 - Layer 1: Creature State Machine

Core Concept: Each creature type behaves differently under specific conditions and states, depending on what those states dictate. For now, they are categorized into three groups (prey, predators and scavengers). In the future, changes could include additions and updates to these documents. These creatures’ behavior varies under observable conditions, such as day and weather cycles.

1.1.1 - Core States

StateCharacteristics
Resting
  • Low activity, reduced movement
  • Found in a sheltered location (caves, dense foliage, nest, etc.)
  • Increased during rain
  • Creatures are less aggressive and easier to approach.
    • Predator: When a predator creature notices the player or another predator while resting, it becomes aggressive.
    • Prey & Scavenger: When the creature detects the player or a predator while resting, it flees or flies away.
Feeding
  • Active foraging/hunting
  • Found in food sources (water, vegetation, fruit bushes, prey shelters, scavengers scavenging the corpse of other creatures)
  • Peak activity during sunny conditions.
Migrating
  • Transitional movement between states
  • Creatures move between micro-zones when there is a situation related to that creature. For instance, if the prey creature is in the feeding state, it can move from the opening to the forest edge to eat tasty berries.
  • Follows terrain-based pathways, such as waterways and ridgelines.
  • The most unpredictable state creates variances.
Territorial
  • Defending specific areas.
  • Aggressive toward all intruders.
  • Around nests and sheltered locations.
  • Localised to specific locations.
  • Prey: When the player or another predator enters the prey’s territory, if the prey has an attack chance or can attack (like a deer using its antlers to attack), it will attack to knock the player or the predator down and run away.
Scavenging
  • Drawn to the recent kill sites.
  • Appears after predators or the player’s hunt
  • After the prey dies, after a certain time, if the corpse is not touched, scavengers will spawn and start nibbling it.
Alert
  • Auditory awareness increased
  • They move slowly
  • More reactive to the sound-based threats. A slight sound cue could trigger the prey to transition into the flee state.
Flee
  • Triggers after the creature feels threatened.

State Transition Diagram

State Transition Diagram

Creature TypeMorningMiddayDuskNightPrimary Location
PredatorRestingFeedingFeedingFeedingCaves → Open areas
PreyFeedingRestingFeedingRestingWater → Open Areas →Shelter
ScavangersScavangingRestingScavangingRestingKill Sites → Trees → Caves

1.1.2 - Weather System

WeatherCharacteristics
Sunny (Baseline)
  • Visibility: 100%
  • Audio range: 100%
  • Movement: 100%
  • Normal creature behaviors
  • Standard schedules are followed, and creatures operate at full activity level.
  • Vision-based detection at maximum range
  • Player Strategy: Patterns are more predictable.
Rainy
  • Visibility: 80%
  • Audio Range: 60%
  • Movement: 70%
  • Creatures mostly spawned around shelter, rarely spawned in other areas.
  • Creatures roam less, stay in sheltered areas, and spend most of their time in a resting state.
  • The feeding state is reduced by 60%
  • Movement speed reduced by 30%
  • The rain muffles audio cues.
  • Caves could have groups of predators; players must be careful.
  • Player Strategies: Check shelter locations, check caves, check dense vegetation.
Foggy
  • Visibility: 40%
  • Audio range: 150%
  • Movement: 70%
  • Creatures can enter the alert state more frequently. A slight leaf crunch sound could trigger the flee state.
  • Visual detection is low, auditory detection is high. When the creatures are not in flee mode, they move slowly.
  • Predators rely on ambush tactics. Players could be hunted if they haven’t noticed the predators.
  • Player Strategies: Move slowly and quietly, but be careful; players can also be hunted if they are unaware of the predator.
WeatherMovement SpeedRoaming Radius from the Spawn PointResting PriorityVision RangeHearing Range
Sunny100%100%1.0x100%100%
Rainy70%40%2.0x80%60%
Foggy80%60%1.5x40%150%

Weather System

1.2 - Layer 2: Micro-zoning

Core Concept: Within each biome, there are special micro-zones that determine the creature density and spawn priority. These zones are tied to terrain features.

FeatureDescription
High elevationMore like hills, or mountains. Predators and scavengers hide or rest here.
Dense VegetationDense forests with thick vegetation such as trees, bushes, plants, etc. This zone serves as a resting ground for prey.
Cave EntranceDark tunnels or just an opening; mostly predators rest; sometimes prey can be found here, too. 
Riverside/SeashoreWhere all animals drink or hang out. Still, predators and scavengers hunt and feed here. Also, some predators are in the water to hunt fish.

1.2.1 - Micro-zone types

Micro-ZoneTraitDescription
Water Proximity Zones (Riverside/Seashores)0-50mAll the creatures drink water. Some predators hunt prey or fish in the water.
50-150mPredator ambush zone. Predators could hide in a bush and attack prey or players.
150m+General territory. Where the Valley or Vegetation starts. Prey rest or feeding place, depending on vegetation density.
Elevation ZoneHigh GroundPredators and scavengers' resting place. If territorial, they become aggressive when an outsider approaches.
Mid ElevationMigration paths, predators, and scavengers pass through or rest here during the late hours.
ValleyPrey resting, or feeding place, depending on the density of the vegetation.
Vegetation DensityDenseWhere the prey primarily hide and rest. If there is a prey nest, the prey are territorial. There could also be predators for players to hunt, but players will mainly find prey. During fog and rain, there will be no predators in here.
Forest EdgeWhere the prey feeds on fruits and berries on trees and bushes. Where predators hunt prey.
ClearingsWhere the prey feeds on bushes and grass. Where the predators haunt prey, and scavengers feast on carcasses.
CaveCave EntranceDuring rain, most prey will hide here from the rain. Other than rainy days, there will be no prey. During foggy periods, predators will be here.
Inner CaveA Hide and resting place for predators. Predators in here are territorial because this place also serves as their nest. 

State/Creature

PreyPredatorScavengers
RestingSunny: Dense vegetation
Rain: Dense vegetation and Cave Entrance
Sunny: Inner cave, High Ground and mid elevation
Foggy: Cave Entrance and Inner Cave
High Ground and mid elevation
FeedingClearing and forest edge.Sunny: Mid elevation, Dense vegetation, forest edge, clearings, Water proximity, Zone 1 and Zone 2.
Foggy and Rainy: They won’t enter Dense vegetation.
Mid elevation, forest edge, clearings, Water proximity Zone 1 and Zone 2.
TerritorialDense vegetationInner Cave and High GroundHigh Ground
Scavenging--Mid elevation, forest edge, clearings, Water proximity Zone 1 and Zone 2.
AlertDuring FogDuring FogDuring Fog

1.3 -  Layer 3: Interaction Chains


Core Concept: Creatures interact with each other, which creates readable behavioural changes and environmental clues for the player.

1.3.1 - Prey-Predator Detection Ranges

  • Sunny Weather
    • Creatures' visual detection range will be 100 meters.
    • The audio detection range will be 50 meters. 
  • Foggy Weather
    • Visual Detection will be 40 meters.
    • Audio Detection will be 100 meters.
    • Within 50 meters, a slight leaf crunch will trigger the flee state.
  • Rainy Weather
    • Visual Detection range will be 60 meters. 
    • The audio detection range will be 30 meters.
    • Most of the sounds will be muffled by rain interference. 
    • Within 10 meters, a slight leaf crunch is audible.

1.3.2 - Prey-Prey Interaction

  • During sunny weather, prey will spawn and will stay more dispersed
  • During foggy weather, they spawn and remain more clustered. Herd-like.
  • Some creatures will be designed as herds. (Will be specified later)
  • If herds or herd-like creature groups trigger each other. For instance, if a prey animal detected a predator, triggering the flee state and initiating a run, the rest of the herd would also enter the flee state and run.

1.3.3 - Scavenger Interaction

  • After the player or any other creature kills a creature, scavengers spawn depending on the weather conditions.
  • If the weather is sunny, scavengers will spawn in 5 minutes near the carcass.
  • If the weather is foggy, scavengers will spawn in 7 minutes near the carcass.
  • If the weather is rainy, scavengers will spawn in 10 minutes near the carcass.
Time: 0Kill Occurs
Sunny Weather5 mins: Scavenger arrives
Foggy Weather7 mins: Scavenger arrives
Rainy Weather10 mins: Scavenger arrives
If the carcass is scavengedThe carcass turns to bones, and the bones despawn in 5 minutes
Time: 20+ minsCarcass despawns if not scavenged

1.4 - Layer 4: Environmental Traces

1.4.1 - Physical Traces Timeline


Core Concept: Creatures leave observable traces behind for their presence and movement. Players can observe these traces to predict the creatures' locations or movements.

Sunny: 8 minutes

  • 0 min: 100% visibility.
  • 2 mins: 75% visibility
  • 4 mins: 50% visibility
  • 6 mins: 25% visibility
  • 8 mins: Faded

Rainy: 3 minutes

  • 0 min: 100% visibility
  • 1 min: 50% visibility
  • 2 min: 20% visibility
  • 3 min: washed away

Foggy: 15 minutes

  • 0 min: 100% visibility
  • 5 mins: 65% visibility
  • 10 mins: 33% visibility
  • 15 mins: Faded

1.4.2 - Audio Range by Weather

Audio Detection Comparison:

  • Sunny: Source —-------------------> Player

100m

  • Rainy: Source —-------------------> Player

60m

                                     Muffled by rain

  • Foggy: Source —-------------------> Player

                                               150m

                          Echo Effect, harder to pinpoint

Audio Range Table

WeatherBase RangeModifierEffective RangeDirectionalityPlayer Strategy
Sunny100m1.0x100mClearAccurate tracking
Rainy100m0.6x60mMuffledClose-range only
Foggy100m1.5x150mEchoingWide area search

1.4. - Environmental Disturbance Types

  • Crushed grass: When the creature walks on grass or in a wheat field, it crushes the grass or wheat, indicating its presence.
  • Broken branches: When the creature walks on a tree branch on the ground or near a tree, or breaks a branch, this indicates the creature is nearby. 
  • Disturbed water: Indicates the creature is passing by, or drank a couple of seconds ago, or is still drinking.
  • Mud Tracks: Footprints will spawn on rainy days, and the water will fill them. Due to that, the fresh tracks will last longer. But in the following rain, if the footprints are still alive, they will start to fade away, as explained in 2.4.1
  • Claw Marks: Claw marks indicate that a predator is nearby.

2 - Teaching the System

An essential aspect of this concept is that players should never be instructed or told how to hunt or find creatures. The player should learn this system while observing creature behaviours and patterns. Depending on the player types, there may be multiple hints to guide players in the right direction.

Player Types

  • Explorer
    • Discovers through wandering
    • Needs environmental clues
  • Achievers
    • Challengers are more beneficial
    • Needs quests
  • Socialisers
    • Learns from the NPC
    • Benefits from community knowledge

2.1 - Learning Through Natural Gameplay Loop

Learning Through Natural Gameplay Loop

2.2 - Creature Behaviour Complexity Progression

This section explains the creature behaviours, and to convey the progression to the player, I designed the complexity increase through zone changes. However, when the player reaches the next zone, and its complexity increases, the previous zone's complexity increases as well.

At Zone 1 

  • Creatures have more predictable behaviours. 
  • Creatures make more noise.
  • They can be found in more predictable locations, such as openings, along waterways, cave entrances or near bushes.
  • They react less to the weather conditions.
  • Visual and auditory detection ranges 50% lower than base conditions. As a result, 50% fewer triggers in the flee state.

From Zone 2 to 4

  • Creatures have less predictable behaviour.
  • Creatures make less noise.
  • They can be found in less predictable locations and are more likely to migrate between micro-zones or to areas close to their nests. 
  • Creatures will interact more frequently with one another.
  • They fully respond to weather conditions. 
  • Visual and auditory detection ranges 30% lower than base conditions. As a result, 30% fewer triggers in the flee state.

From Zone 5 to 6

  • Creatures have less predictable behaviour.
  • Creatures will fully interact with each other.
  • Visual and auditory detection ranges 10% lower than base conditions. As a result, 10% fewer triggers in the flee state.

From Zone 7 to 8

  • Every behaviour will be in the base conditions, as explained in the previous section.

Design Notes

  • Instead of zones, playing time could be used to set the complexity progression. 
  • Instead of zones, experience level could be used to set the complexity progression.

2.3 - NPC Dialogue with Subtle Hints

Hint Types

  • Weather: NPC explains the creature's behaviours during the weather changes between texts. 
  • Hunter Wisdom: NPC gives subtle hints on prey behaviour and patterns.
  • Old Tales: Tells old tales that caution the player on scavenger and predator behaviour and patterns.
  • Self Thought: The PC that talks by itself with the observations depending on the pattern findings.

2.4 - Quest Design for Teaching

Teaching quest sequence examples

  • Q1 - Teaches: Location of the creatures and what they do during a specific time frame.
  • Q2 - Teaches: Creatures' behaviour during the weather changes.
  • Q3 - Teaches: Creatures’ audio cues 
  • Q4 - Teaches: Environmental traces left by creatures.
  • Q5 - Teaches: Creature interactions with each other.

)))