Environmental Interaction System

1. Summary

An environmental layer system that defines terrain affordances, concealment, weather effects, and interactive objects across mission levels. It governs how bushes, hedges, and building interiors hide characters and bodies; how snow leaves temporary footprints that enemies follow; how water, vines, ladders, and grappling hooks enable or block traversal by movement archetype; how darkness, torchlight, and rain alter visibility and noise; and how interactive objects (barrels, rocks, icicles, carts, cranks, cloth barriers) can be manipulated to create accidents, open paths, or dispose of bodies permanently in wells or deep water.

2. Tags

3. Design Intent / Job Story

When planning a stealth approach through a guarded area, I want to use the environment to conceal my team, manipulate enemy patrols, and create accidents, so that I can complete objectives without raising alarms.

4. Role in Gameplay Loop

• Provides the spatial and environmental foundation for all stealth tactics in every mission
• Creates tactical opportunities through verticality (rooftops, vines, ladders), concealment (bushes, hedges, interiors), and destructible or movable objects
• Gates character capabilities based on movement archetype (agile vs heavy) through terrain affordances
• Supports the Mission Badge System with environmental constraints ("Don't enter the water", "Don't step on loud surfaces", "Extinguish all torches")
• Enables creative problem-solving by allowing players to lure enemies with footprints, drop objects from above, or hide bodies in permanent removal zones

5. Preconditions

• Mission level has loaded with environmental affordances (concealment spots, climb surfaces, water, interactive objects) placed by level design
• Weather and lighting conditions (day/night, snow, rain, torch presence) are configured per level
• At least one player-controlled character is alive and present in the mission
• Character movement archetype matches the environmental affordance they attempt to use

6. Parameters

7. Core Rules

• Concealment Spots: Bushes, hedges, and building interiors function as concealment spots. Characters inside are hidden from enemy vision cones. Bodies placed inside concealment spots are hidden from enemy discovery.
• Snow Footprints: Moving across snow-covered terrain leaves temporary visible footprints. Enemies who spot footprints will follow the trail to its endpoint and enter investigation. Footprints fade automatically after a short duration.
• Water and Swimming: Water bodies can be swum through by agile archetype characters. Entering water breaks disguises. Standing water produces splash noise when characters run through it. Bodies dumped in deep water are permanently removed.
• Verticality — Vines and Ladders: Vines can be climbed by agile archetype characters. Ladders can be climbed by all characters. Rooftops and elevated positions enable death-from-above attacks and allow bypassing ground patrols.
• Grappling Hooks and Rope Ladders: Hook-rings in the environment allow agile characters to ascend to rooftops or cross gaps. Rope ladders can be lowered by agile characters to allow heavy archetypes to follow.
• Light and Darkness: Darkness reduces enemy vision range. Torches and fires create localized bright zones that restore full vision within their radius. Torches can be extinguished by characters; guards may leave their post to relight them.
• Weather — Rain: Rain reduces enemy vision range and limits player sight distance. Footsteps on wet or muddy ground produce more noise than on dry terrain.
• Interactive Objects — Heavy Objects: Explosive barrels, rocks, and heavy stones can be carried by heavy archetypes and thrown horizontally or vertically to crush enemies or create explosions. Nearby guards treat these as accidents.
• Interactive Objects — Drop Traps: Icicles, hanging crates, rocks, and vases positioned above enemies can be dropped onto targets below, killing them as accidents that do not trigger alarms.
• Interactive Objects — Mechanisms: Cranks can drop wood stacks, open gates, or move cages. Scaffolding can be knocked over to flush out or kill enemies.
• Wagons and Carts: Characters can hide inside stationary carts. Carts and wagons block enemy line of sight. Moving wagons provide mobile cover and can transport characters across areas.
• Doors: Doors can be opened and closed. Characters can hide behind closed doors. Doors block enemy vision when closed.
• Cloth Barriers: Fabric fences and cloth walls can be cut open by any character to create new traversal paths.
• Permanent Removal Zones: Wells, deep water, and cliffs permanently remove bodies from play when bodies are thrown into them, preventing any future discovery.
• Loud Surfaces: Certain surfaces (puddles, specific floor types) produce amplified footstep noise when characters run across them.
• Disguise Sources: Clothing and laundry placed in the environment can be interacted with to acquire disguises. Acquisition is character-specific and may require eliminating or knocking out nearby civilians first.

8. BDD Scenarios

9. Edge Cases

• A character enters a bush while already inside an enemy's vision cone; detection buildup pauses but does not reset until line of sight is fully broken
• Snow footprints from multiple characters cross; enemies follow the most recent or most visible trail, potentially leading to an empty ambush spot
• A guard relights a torch that was extinguished, restoring vision range in that area and potentially spotting a character who relied on the darkness
• A heavy archetype is ordered to a destination reachable only by swimming; pathfinding must reroute or the command must fail gracefully
• A body thrown into a well or off a cliff is permanently removed and cannot be retrieved, even if the player later needs to move it
• A character starts climbing a vine just as a guard turns toward them; the climbing animation may expose them if the vine is in the guard's vision cone
• Rain and darkness weather effects may stack, resulting in significantly reduced enemy vision range
• An interactive object (barrel, rock) thrown by a heavy character may land in an unreachable location, preventing retrieval and potentially blocking the object for the mission
• A cart that the player is hiding inside begins moving; the character remains hidden but may be transported to an unexpected location
• A door used for hiding is opened by a patrolling guard, exposing any character hiding behind it
• Disguise clothing can only be acquired from specific environmental points; if the civilian guarding the clothes is not eliminated or knocked out first, acquiring the disguise may trigger detection
• A trap placed inside a bush automatically conceals the victim, but if the bush is already occupied by another body, visual clipping or discovery may occur
• Standing in a puddle while running produces amplified noise that can alert guards outside the normal footstep radius
• A rope ladder lowered for a heavy character may be retracted if the agile character moves away, stranding the heavy character
• Environmental drop traps (icicles, rocks) require precise positioning; if the target moves before the drop completes, the object may miss and alert guards with its impact noise

10. QA Notes

11. Mechanic Dependencies

• Stealth Detection System (environmental conditions (darkness, snow footprints, torchlight, rain) directly modify the parameters of the Stealth Detection System's vision cones and noise evaluation)
• Stealth Elimination Mechanics (environmental eliminations (falling objects, poisoned items, animal kicks, heavy object throws) depend on interactive objects placed by this system; trap placement in concealment spots auto-hides victims)
• Body Manipulation Mechanics (concealment spots (bushes, hedges, wells, doors, water) and permanent removal zones (wells, cliffs, deep water) are environmental features that the Body Manipulation system uses to hide or dispose of bodies)
• Character Movement System (traversal options (vine climbing, swimming, rooftop jumping, grappling hook use, ladder climbing) are gated by environmental affordances defined in this system)

12. UI Links

• Enemy Vision Cones - The Environmental Interaction System dynamically modifies vision cone properties: darkness shrinks cones, torchlight extends them, rain reduces vision range, and bushes/concealment spots hide characters within active cones. Environmental occlusion (walls, fences, rocks) clips cone geometry in real-time.

References

1. 1.

   The Art of Shadow Tactics Blades of the Shogun and STRATEGY GUIDE (L600-4200 of 4930) Extensive strategy guide covering environmental mechanics including bushes, hedges, vines, ladders, rooftops, snow footprints, water, swimming, carts, barrels, wells, torches, darkness, rain, icicles, rocks, cloth barriers, and disguises.After a short leap across a gap, climb the vines at (1.1), jump down, then up at (1.2). At (1.3) another jump down leads to the fi rst scroll informing about the mission log. After...

2. 2.

   Shadow Tactics: Blades of the Shogun Review – Is This the Best Version Yet? (7:20-7:40) Review confirms guards follow footprint trails and search bushes when suspicious.