Vampire-Act-Base/design/gdd/death-respawn-rules.md

Death/Respawn Rules

Status: In Design Author: SepComet + Claude Last Updated: 2026-04-27 Implements Pillar: 操作优于数值 (Skill Over Stats), 切换即承诺 (Switch is Commitment)

Overview

Death/Respawn Rules 是夜裔的玩家死亡与重生管理系统——定义玩家如何承受伤害、何时死亡、在何处重生、以及死亡带来的代价。它与"切换即承诺"支柱直接对齐：死亡惩罚的设计目标是让玩家在切形态时感受到风险（切错了可能死），但不会让死亡变成挫折（快速重生，代价合理）。系统采用 checkpoint 重生模型：玩家死亡后在最近的检查点重生，失去所有当前血能，当前波次重置——但不会失去关卡进度或任何永久升级。

玩家直接感受死亡时刻的冲击和重生时刻的重新出发。死亡不是"你输了"——屏幕短暂变暗、血能归零、你在检查点重新站起、敌人重新列阵。这个循环参考 Celeste 的"失败是学习"哲学——死亡足够轻，让你敢于尝试高风险操作（弹反时机、形态切换窗口）；但足够重，让你在意每一次切换的决策。没有这个系统，形态切换的风险维度崩塌——玩家可以无代价地随意切换，违背"切换即承诺"支柱。

Player Fantasy

Death/Respawn Rules 服务于一个动作游戏中最被低估的情感："再来一次"的渴望。当你因切形态时机错误被 Brute 一拳砸死时，那一瞬间不是挫败——是"我知道了，下次弹反要早 0.1 秒按"。屏幕暗下、血能归零、你在检查点重新站起的 2 秒内，你已经在大脑里重放了刚才的失误并找到了修正方案。这就是好的死亡系统应该创造的感受：死亡不是终点，是信息。

参考 Celeste 的死亡哲学——"每次死亡都是学习，重生快到你不觉得被打断"——和 Hades 的死亡循环——"死亡是回家，不是失败"。夜裔的死亡走在两者之间：Celeste 的快速重生（检查点即重生，没有加载、没有菜单） + Hades 的资源重置（血能归零是实质性代价，迫使你重新赚取）。玩家敢于尝试高风险操作——极限弹反、狼形对撞、雾形深入包围——因为这些操作失败后的惩罚是有限的、可量化的、可恢复的。你不会因为一次失误而失去 30 分钟的进度，你只会失去当前的血能和当前波次——然后你立刻重新开始。

Detailed Design

Core Rules

1. Player Health

• MaxHealth: 100 (baseline, before any upgrades)
• CurrentHealth: tracked by Death/Respawn Rules, range [0, MaxHealth]
• Health displayed to player via HUD, driven by OnPlayerHealthChanged(current, max) event

2. Player Damage Reception Pipeline

Enemy AI produces AttackData → CombatCoordinator.ResolveFrame() → OnPlayerHit → Death/Respawn subtracts health

• Combat Logic's CombatCoordinator.ResolveFrame(deltaTime) handles all attack resolution (player + enemy) in a unified two-phase pipeline
• Enemy attacks are resolved against PlayerState during the damage phase (after parry nullification in the parry phase)
• Death/Respawn Rules subscribes to CombatLogic.OnPlayerHit(PlayerDamageResult) — subtracts FinalDamage from CurrentHealth
• No player-side resistance or armor — damage is applied as-received (mirrors Enemy AI's pure-receiver model)

3. PlayerState Definition

PlayerState is defined in Combat Logic GDD (authoritative single source). Death/Respawn reads and writes these fields:

• Reads: Position, HitShape (provided to CombatCoordinator for hit detection)
• Writes: CurrentHealth (updated on damage), MaxHealth (baseline 100, modified by upgrades), IsDead (set when CurrentHealth <= 0), IsInvincible (set during respawn i-frames)
• Other PlayerState fields (FacingAngle, IsParryActive, ParryShape) are managed by Form Switch SM and Combat Logic; Death/Respawn does not touch them.

4. Death Condition

• CurrentHealth <= 0 → player dies
• Death is immediate on the frame health reaches 0
• Player cannot act during death (all input ignored)
• Trigger sequence: OnPlayerDied → systems react → respawn timer starts

5. Checkpoint System

• Checkpoint = start of current wave
• Updated each time OnWaveChanged fires (Wave Manager)
• On death: player respawns at the checkpoint wave's start state
• No manual checkpoint activation needed — automatic, invisible

Death State

Phase	Duration	What Happens
Death Freeze	0.3s	Screen freeze-frame. Player input locked. OnPlayerDied emitted.
Death Fade	1.0s	Screen fades to black. Audio ducks. Systems react (enemies stop, blood energy resets).
Respawn Fade	0.5s	Player repositioned at checkpoint. HUD resets. OnPlayerRespawned emitted.
Invincibility	2.0s	Player can move and act but takes no damage. Visual: player geometry pulses/flashes.
Active	—	i-frames expire. Full damage vulnerability restored. OnPlayerVulnerable emitted.

Total death-to-active: ~3.8 seconds. Fast enough to feel like "instant retry."

Respawn Flow

1. Player dies → OnPlayerDied emitted
2. Blood Energy Economy receives OnPlayerDied → resets blood energy to 0
3. Wave Manager receives OnPlayerDied → freezes wave state
4. Death fade completes → player position reset to checkpoint spawn point
5. Wave Manager receives OnPlayerRespawned → resets current wave (despawn all enemies, restart from InterWave)
6. Player enters Invincibility (2s)
7. OnPlayerVulnerable → player fully active, wave restarts

Interactions with Other Systems

System	Direction	Interface
Combat Logic	Upstream	Provides PlayerState to Combat Logic as hit target. Receives OnPlayerHit(PlayerDamageResult) for health subtraction.
Blood Energy Economy	Downstream	Emits OnPlayerDied → Blood Energy resets to 0.
Wave Manager	Downstream	Emits OnPlayerDied (wave freezes), OnPlayerRespawned (wave resets to current checkpoint wave).
Enemy AI Logic	Downstream	Emits OnPlayerDied → all enemies enter Cooldown/Idle. Emits OnPlayerVulnerable → enemies resume normal behavior.
Form Switch SM	Downstream	Emits OnPlayerDied → resets form to default (Human) on respawn.
UI/HUD (L2)	Downstream	Emits OnPlayerHealthChanged, OnPlayerDied, OnPlayerRespawned, OnPlayerVulnerable for HUD display.
VFX Spawner (L1)	Downstream	Emits OnPlayerDied (death VFX), OnPlayerRespawned (respawn VFX).
Audio Player (L1)	Downstream	Emits OnPlayerHit (pain SFX), OnPlayerDied (death sting), OnPlayerRespawned (respawn whoosh).

Formulas

Player Damage Reception

The player damage formula is defined as:

newHealth = currentHealth - finalDamage

Variables:

Variable	Symbol	Type	Range	Description
Current health	currentHealth	float	0–100	Pre-hit health
Final damage	finalDamage	float	0–150	From Combat Logic PlayerDamageResult

Output Range: 0–100 | Clamped at 0. If newHealth <= 0 → IsDead = true, OnPlayerDied fires.

Design Intent: Player applies damage as-received — no armor, no resistance, no mitigation. Transparency: a Brute hit always does exactly 25 damage. The player always knows how many hits they can take. Skill expression is in avoiding/parrying hits, not in building damage resistance.

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Death Threshold

The death formula is defined as:

isDead = currentHealth <= 0

Output: Boolean. Once true, triggers the full death→respawn sequence. OnPlayerDied fires exactly once per death.

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Hit Survival Thresholds (Baseline 100 HP)

Enemy Attack	Damage	Hits to Die
Swarm	6	17
Stalker	18	6
Brute	25	4

Design Intent: Brute is always lethal in 4 hits — enough to create tension but enough time to learn the parry timing. Swarm chip damage adds up — ignoring them is viable short-term but fatal if sustained.

Edge Cases

• If player takes damage exceeding current health (overkill): Health clamps to 0. No negative health. Death triggers once. Overkill damage is not tracked — does not affect respawn.
• If player takes damage while IsInvincible=true (respawn i-frames): Damage ignored. OnPlayerHit does NOT fire. Health unchanged.
• If multiple hits kill the player in the same frame (simultaneous hits from multiple enemies): All hits resolve (batched frame). Health drops to 0 or below. OnPlayerDied fires exactly once. Hit events for the same frame after death are still emitted but health stays at 0.
• If deltaTime = 0 (game paused): Death/respawn timers (Death Freeze, Death Fade, Respawn Fade, Invincibility) all pause. No phase transitions during pause.
• If player dies on Wave 1 (first wave, checkpoint = Wave 1 start): Normal respawn flow applies. Blood energy already 0 or low. Wave 1 restarts. No special case needed.
• If player dies during Invincibility (2s i-frames): Cannot happen — player is invincible. No damage received.
• If OnPlayerDied fires but OnPlayerRespawned never fires (e.g., game quit during death): State is discarded. Next session starts fresh. No partial death state persists.
• If MaxHealth is modified (future Skill Tree upgrade) while player is dead: Applied on respawn. CurrentHealth = new MaxHealth on respawn.
• If checkpoint advances (OnWaveChanged) during death animation: Ignored. Checkpoint only updates while player is in Active state. Death-locks checkpoint at the wave where death occurred.

Dependencies

System	Layer	Type	Hard/Soft	Interface
Combat Logic	L0	Upstream	Hard	Provides PlayerState for hit detection. Receives OnPlayerHit for health subtraction. Cannot function without damage pipeline.
Blood Energy Economy	L0	Downstream	Hard	Emits OnPlayerDied → resets blood energy to 0. Core death penalty mechanic.
Wave Manager	L0	Downstream	Hard	Emits OnPlayerDied (freeze), OnPlayerRespawned (reset wave). Wave reset is the other core death penalty.
Enemy AI Logic	L0	Downstream	Soft	Emits OnPlayerDied → enemies stop attacking. Works without but enemies attacking a corpse looks broken.
Form Switch SM	L0	Downstream	Soft	Emits OnPlayerDied → form resets to Human on respawn.
UI/HUD (L2)	L2	Downstream	Soft	Emits OnPlayerHealthChanged, OnPlayerDied, OnPlayerRespawned for display.
VFX Spawner (L1)	L1	Downstream	Soft	Emits death/respawn events for visual feedback.
Audio Player (L1)	L1	Downstream	Soft	Emits hit/death/respawn events for audio feedback.
Level Loader (L1)	L1	Upstream	Soft	Receives checkpoint spawn positions from LevelData.

Hard dependencies: Combat Logic, Blood Energy Economy, Wave Manager.

Tuning Knobs

Parameter	Default	Safe Range	Too Low	Too High
MaxHealth	100	60–150	Every hit feels lethal — no learning window	Player immortal — no tension
DeathFreezeDuration	0.3s	0.1–0.5s	No impact feel — death feels glitchy	Too long — feels unresponsive
DeathFadeDuration	1.0s	0.5–1.5s	Not enough time for audio cue	Player waiting — frustration builds
RespawnFadeDuration	0.5s	0.3–1.0s	Disorienting — player doesn't register new position	Dead air before action resumes
InvincibilityDuration	2.0s	1.0–3.0s	Spawn-camped by enemies at perimeter	Too safe — player can clear enemies during i-frames
PlayerHitShapeRadius	0.5	0.3–0.7	Too hard to hit — attacks whiff unfairly	Too easy to hit — player feels bloated

Key tuning pair: MaxHealth + enemy AttackBaseDamage values (in Enemy AI GDD). Changing MaxHealth changes every hits-to-die threshold. Baseline (non-crit worst case): Swarm=100/6≈17 hits, Stalker=100/18≈6 hits, Brute=100/25=4 hits. Actual hits-to-die varies with player crits, positional guarantees, and form-specific damage.

Visual/Audio Requirements

Combat is a visual system — Visual/Audio is REQUIRED.

Event	VFX	Audio
OnPlayerHit	Red flash at screen edge from hit direction. Player geometry briefly flashes red.	Pain SFX — varies by damage amount (light grunt <15, heavy grunt ≥15)
OnPlayerDied	Screen freeze-frame (0.3s) → player geometry shatters outward in white/silver fragments	Bass drop + silence — distinct from enemy death sounds
OnPlayerRespawned	Player geometry reforms from fragments at checkpoint position. White flash → form color transition.	Rising whoosh + heartbeat start
OnPlayerVulnerable	Player geometry stops pulsing/flashing. Brief shimmer.	Subtle "ready" chime
OnPlayerHealthChanged	Health bar VFX (flash on damage, gentle pulse on low health <25%)	None (too frequent for SFX)

Invincibility visual: Player geometry pulses white at 4Hz during i-frames. Intensity decreases over the 2s duration — last 0.5s is barely visible.

UI Requirements

Element	Content	Trigger
Health Bar	CurrentHealth / MaxHealth as horizontal bar. Color: green (>50%), yellow (25-50%), red (<25%).	OnPlayerHealthChanged
Death Overlay	Full-screen dark vignette + "You Died" text (1s)	OnPlayerDied
Respawn Text	"Again" — centered, fades after 1s	OnPlayerRespawned
i-Frame Indicator	Health bar border pulses white during invincibility	OnPlayerRespawned → OnPlayerVulnerable

Acceptance Criteria

#	GIVEN	WHEN	THEN
1	Player CurrentHealth=100. PlayerDamageResult { FinalDamage=25 }.	OnPlayerHit received	CurrentHealth=75. OnPlayerHealthChanged(75, 100) fires. IsDead=false.
2	Player CurrentHealth=20. PlayerDamageResult { FinalDamage=25 }.	OnPlayerHit received	CurrentHealth=0 (clamped). IsDead=true. OnPlayerDied fires. Death sequence begins.
3	Player CurrentHealth=10. Two simultaneous hits: FinalDamage=8 and FinalDamage=6.	Both hits in same frame	CurrentHealth=0. OnPlayerDied fires exactly once. Both OnPlayerHit events fire.
4	Player IsInvincible=true (during respawn i-frames). PlayerDamageResult { FinalDamage=25 }.	OnPlayerHit received	Damage ignored. CurrentHealth unchanged. OnPlayerHealthChanged does NOT fire.
5	Player dies. Death Freeze(0.3s) → Death Fade(1.0s) → Respawn Fade(0.5s) → Invincibility(2.0s).	Death sequence completes	Total elapsed ~3.8s. Player is at checkpoint position, full health, form=Human.
6	Player dies on Wave 3. Checkpoint = Wave 3.	Respawn completes	Wave Manager.OnPlayerRespawned fires → Wave 3 resets from InterWave. Blood energy = 0.
7	Player in Active state. Wave 4 starts (OnWaveChanged fires).	Checkpoint update	CurrentCheckpointWave = 4. Future death respawns at Wave 4.
8	deltaTime=0.0 during Death Fade (0.5s elapsed, 0.5s remaining).	Update called	Timer does not advance. Death Fade stays at 0.5s remaining.
9	Player CurrentHealth=100. MaxHealth increased to 120 (future upgrade).	Upgrade applied	MaxHealth=120. CurrentHealth stays 100. (Does not auto-heal on upgrade.)
10	Player dies at MaxHealth=120.	Respawn completes	CurrentHealth = MaxHealth = 120 (full heal on respawn).

Open Questions

• Respawn position within arena: Should the player respawn at arena center, or at a designer-specified spawn point per wave? MVP defaults to arena center. Defer spawn point customization to Level Loader GDD.
• Should there be a "death streak" mechanic (e.g., slight health buff after 3 consecutive deaths on same wave)? Aligns with Celeste philosophy of helping struggling players, but may conflict with "Skill Over Stats" pillar.
• Player HitShape (Circle r=0.5): Is this the same regardless of current form? Or should HitShape change with form (Human smaller, Wolf larger, Mist diffuse)? MVP uses uniform HitShape for simplicity.
• Should the death counter be tracked for scoring/statistics? Score Calculator GDD may want this data.
• Game Over condition: Is there one? Infinite retries is the MVP plan, but should a level have a max-death count for challenge mode? Defer to Score Calculator / Menu System.