# Scenario Examples

## 1. **Left 4 Dead – “The AI Director”**

{% @mermaid/diagram content="flowchart TD
A\[RuntimeSpawner<br>Ambient commons] --> B\[SpawnDirector<br>Ramping intensity]
B --> C\[Mission trigger]
C --> D\[Crescendo wave]
C --> E\[Background trickle]
B --> S1\[Hunter or Smoker<br>Flank tags, LOS limits]
D --> S1
D --> S2\[Tank<br>High pressure and late step]
S1 --> F\[Short danger bursts]
S2 --> G\[Boss pressure windows]
E --> H\[Constant background noise]
D --> I\[Unpredictable spikes]
" %}

* **Baseline**:
  * RuntimeSpawner set up with **ambient global spawns** of common infected.
  * SpawnDirector profile slowly ramps alive cap & spawn rate as the team progresses.
* **Waves**:
  * Trigger volumes (in mission scripting) call `StepUp()` to escalate difficulty.
  * Sudden spikes in intensity simulate “crescendo” moments.
* **Specials**:
  * Special Profile with rules like:
    * **Hunters/Smokers** (require LOS constraints, spawn flank tags).
    * **Tanks** (min pressure gate, step range late-game only).

End result: Constant “background noise” of zombies, punctuated by waves and unpredictable specials.

***

## 2. **Payday 2 – Police Waves & Specials**

{% @mermaid/diagram content="flowchart TD
A\[RuntimeSpawner] --> B\[Wave Set<br>Police assault]
B --> C\[Director Profile<br>High-rate → Cooldown loop]
C --> D\[Assault burst]
C --> E\[Regroup / Lull]

```
subgraph Specials
  S1[Cloaker<br>Pressure < 0.7<br>Cooldown 120 s]
  S2[Taser<br>Pressure < 0.7<br>Cooldown 120 s]
end

E --> S1
E --> S2
D --> C

D --> F[Sustained firefight]
E --> G[Breathing window<br>Ammo / reposition]
```

" %}

* **Baseline**:
  * RuntimeSpawner configured for **bursts of police waves** (attack → regroup → attack).
  * Director profile: step curve that alternates high spawn rate → cooldown windows.
* **Specials**:
  * Cloakers / Tasers as rules:
    * Spawn only if pressure < 70% (to punish relaxed players).
    * Cooldown 120s per special type.
* **Design Note**:
  * The pacing isn’t just escalation → it *breathes*. High intensity waves alternate with lulls, encouraging ammo scavenging.

***

## 3. **GTFO – Alarm Events**

{% @mermaid/diagram content="flowchart TD
A\[RuntimeSpawner<br>Quiet baseline] --> B\[Alarm check]
B --> C\[Exploration low pressure]
B --> D\[Director set step to climax]
D --> E\[Alarm wave high density]
E --> S1\[Big boys<br>Spawn behind LOS blockers]
E --> S2\[Strikers<br>Close quarters]
E --> F\[Intense holdout]
F --> G\[Alarm clears reset step]
G --> C
" %}

* **Baseline**:
  * Spawner mostly quiet until alarms are triggered.
  * Alarm triggers call `SetStep()` directly, skipping escalation to **climax settings**.
* **Specials**:
  * Add rules for “Big Boys” or “Strikers” that spawn behind LOS blockers when alarms are active.
* **Variation**:
  * Step profile resets after alarms, so intensity can *drop* back to ambient exploration.

&#x20;Teaches designers: The Director doesn’t need to be linear. It can jump or reset on command.

***

## 4. **Horde Survival (Generic Tower Defense)**

{% @mermaid/diagram content="flowchart TD
A\[SpawnDirector<br>AutoByTime: +1 step / 30s] --> B\[Step N<br>Alive cap up, rate up]
B --> C\[RuntimeSpawner<br>Waves escalate]
C --> D{Every 3 steps?}
D -->|Yes| E\[Boss rule<br>Min gap 120s]
D -->|No| F\[Standard waves]

```
B --> S1[Suicider<br>Avg HP > 0.8<br>Prevent early snowball]

E --> G[Boss showdown]
F --> H[Increasing difficulty]
```

" %}

* **Baseline**:
  * SpawnDirector runs AutoByTime every 30s → each step increases alive cap and spawn rate.
* **Specials**:
  * Boss rule triggers every 3 steps (min gap = 120s).
  * “Suiciders” spawn only when avg player HP > 80 (to prevent snowballing too early).

Easy to set up escalating survival modes with replayable structure.

***

## 5. **Dynamic Sandbox Encounters (Far Cry style)**

{% @mermaid/diagram content="flowchart TD
A\[RuntimeSpawner<br>Ambient wildlife / patrols] --> B\[Director Step 0<br>Flat pacing]
B --> C\[Roaming encounters]

```
subgraph Specials
  S1[Miniboss Animal<br>Spawn if LOS blocked & low HP]
  S2[Elite Squad<br>Spawn on tag-matched hint]
end

C --> S1
C --> S2

S1 --> D[Ambush moment]
S2 --> E[Emergent skirmish]
```

" %}

* **Baseline**:
  * Small ambient spawns of wildlife or patrols.
  * Director may be fixed at Step 0 (flat, non-escalating).
* **Specials**:
  * Rules for miniboss animals or elite squads spawn only when conditions line up (player low HP, LOS blocked).

Shows that Specials can also work **without a Director** — pure condition-based encounters.

***

### **Key Takeaways**

* **Spawner = baseline content**
* **Director = pacing & escalation**
* **Specials = conditional spice**

By mixing these three systems differently, you can reproduce:

* *Left 4 Dead*’s reactive director
* *Payday*’s breathing combat rhythm
* *GTFO*’s alarm-based climaxes
* Classic *Horde / Survival* loops
* Open-world emergent encounters