RTS Opponent AI

Play against the computer

Enemy Masses RTS AI

The EnemyMassesRTSAI is a server-controlled AI opponent designed for RTS games. It provides autonomous control of non-player factions with intelligent tactical decision-making, including exploration, combat engagement, retreat behavior, and advanced baiting/trapping tactics.

---

Overview

The RTS AI acts as a computer-controlled opponent that manages its own faction of agents, making decisions based on:

• Force ratios – Comparing army sizes to decide when to engage or retreat

• Tactical awareness – Using advanced maneuvers like baiting and trapping

• AoE threat detection – Automatically spreading formations against area-of-effect attacks

• Difficulty scaling – Adjustable intelligence and reaction times

┌─────────────────────────────────────────────────────────────┐
│                    RTS AI State Machine                     │
├─────────────────────────────────────────────────────────────┤
│                                                             │
│                         ┌────────┐                          │
│                         │  Idle  │                          │
│                         └───┬────┘                          │
│                             │                               │
│              ┌──────────────┼──────────────┐                │
│              ▼              ▼              ▼                │
│       ┌───────────┐  ┌───────────┐  ┌───────────┐          │
│       │ Exploring │  │ Engaging  │  │SettingTrap│          │
│       └─────┬─────┘  └─────┬─────┘  └─────┬─────┘          │
│             │              │              │                 │
│             │              ▼              ▼                 │
│             │       ┌───────────┐  ┌───────────┐           │
│             │       │Retreating │  │  Baiting  │           │
│             │       └─────┬─────┘  └─────┬─────┘           │
│             │              │              │                 │
│             └──────────────┴──────────────┘                 │
│                            │                                │
│                    ┌───────▼───────┐                        │
│                    │  Regrouping   │                        │
│                    └───────────────┘                        │
└─────────────────────────────────────────────────────────────┘

---

Quick Start

Adding the RTS AI to Your Scene

1. Create the AI Controller:

   • GameObject → Enemy Masses → RTS AI Controller

2. Configure Faction Control:

   • Set Controlled Factions to the factions the AI should command

   • Set Enemy Factions or enable Auto Detect Enemy Factions to identify targets

3. Assign References:

   • Link the Crowd Controller (auto-detected if not set)

   • Link the Player RTS Controller for automatic enemy faction detection

// Access the RTS AI at runtime
EnemyMassesRTSAI ai = FindObjectOfType<EnemyMassesRTSAI>();

// Check current state
Debug.Log($"AI State: {ai.CurrentState}");
Debug.Log($"AI Controls: {ai.ControlledAgentCount} agents");
Debug.Log($"Facing: {ai.EnemyAgentCount} enemies");

---

AI States

State	Description	Behavior
Idle	No active objective	Waits for enemies or transitions to exploration
Exploring	Scouting the map	Moves to random points within exploration radius
Engaging	In combat	Aggressively attacks enemy forces
Retreating	Falling back	Moves away from threats when outnumbered
Regrouping	Consolidating forces	Gathers scattered units before next action
SettingTrap	Positioning ambush	Moving main force to ambush position
Baiting	Luring enemies	Using small bait force to draw enemies into trap

---

Inspector Settings

References

Property	Description
Crowd Controller	The EnemyMassesCrowdController to command. Auto-detected if null.
Player RTS Controller	Reference to identify player-controlled factions as enemies.

---

Faction Control

Property	Description
Controlled Factions	Factions that this AI is allowed to control.
Enemy Factions	Factions to attack (used when auto-detect is disabled).
Auto Detect Enemy Factions	Automatically treats player-controlled factions as enemies.

When Auto Detect Enemy Factions is enabled, the AI reads faction data from the referenced EnemyMassesRTSController to determine which factions are hostile.

---

Difficulty Settings

Property	Range	Description
Difficulty	0-5	AI difficulty level (Beginner → Nightmare). Affects tactical decisions and timing.
Decision Interval	0.1-2s	How often the AI makes decisions. Lower = more responsive but higher CPU.
Decision Variance	0-0.5s	Random variance in decision timing for less predictable behavior.

Difficulty Levels

Level	Name	Behavior
0	Beginner	Rarely uses tactics, slow reactions
1	Easy	Occasional tactics, moderate reactions
2	Normal	Balanced tactical use, standard reactions
3	Hard	Frequent tactics, faster reactions
4	Expert	Advanced tactics, quick reactions
5	Nightmare	Maximum tactical intelligence, instant reactions

---

Exploration Settings

Property	Range	Description
Enable Exploration	bool	Enable map exploration when not in combat.
Exploration Radius	10-200	Radius around current position to explore.
Exploration Duration	5-60s	How long to explore an area before moving on.
Min Exploration Distance	5-50	Minimum distance to travel for a new exploration target.

---

Combat Tactics

Property	Range	Description
Enable Advanced Tactics	bool	Enable baiting, trapping, and flanking behaviors.
Min Agents For Baiting	5-100	Minimum agents required to attempt baiting tactics.
Bait Percentage	1-20%	Percentage of forces to use as bait.
Bait Retreat Distance	10-100	Distance bait units retreat to lure enemies.
Engagement Range	10-100	Engage enemies when within this range.
Retreat Ratio	1.5-5.0	Retreat when outnumbered by this ratio.
Regroup Distance	20-100	Regroup when forces spread beyond this distance.

Retreat Ratio Example: With a ratio of 2.5, the AI will retreat when enemies outnumber it 2.5:1 (e.g., 100 AI agents vs 250+ enemies).

---

AoE Avoidance (Formation Spacing)

The AI can automatically detect AoE (Area of Effect) threats from enemy factions and spread out formations to minimize damage.

Property	Range	Description
Enable AoE Avoidance	bool	Enable dynamic formation spacing.
Normal Spacing	0.5-3	Formation spacing when no AoE threat detected.
Spread Spacing	2-6	Spread out spacing when AoE threat detected.
Max Spread Spacing	4-10	Maximum spacing against heavy AoE threats.
Spacing Adjustment Speed	0.5-5s	How quickly spacing adjusts to threats.
Auto Detect AoE Threats	bool	Automatically scan enemy EnemyCrowd settings for AoE.
Manual AoE Threat Level	0-1	Manual override when auto-detect is disabled.
AoE Threshold Radius	1-10	Minimum damage radius to consider as AoE threat.

How AoE Detection Works

When Auto Detect AoE Threats is enabled, the AI scans enemy faction EnemyCrowd configurations for:

1. Projectile AoE – Checks projectileConfig.enableAOE and aoeRadius

2. Secondary Projectile AoE – Checks secondary attack configs

3. Arc Projectiles – Grenades/catapults using ProjectileArc mode get extra threat weight

4. Multiple AoE Factions – Threat level increases with more AoE-capable enemies

Threat Level Visualization:

0.0 ────────────── 0.3 ────────────── 1.0
│                   │                  │
│   Normal         │     Spread       │   Max Spread
│   Spacing        │     Spacing      │   Spacing
│                   │                  │
└──────────────────┴──────────────────┘

---

Spawning (Optional)

The AI can spawn reinforcements over time to replenish losses.

Property	Range	Description
Enable Spawning	bool	Enable AI-controlled spawning of reinforcements.
Max Agent Count	10-1000	Maximum total agents the AI can have at once.
Spawn Wave Size	1-100	Agents to spawn per wave.
Spawn Interval	5-300s	Minimum seconds between spawn waves.
Spawn Formation	enum	Formation type for spawned agents.
Spawn Location	Transform	Spawn location. If null, spawns near existing forces.

---

Visual Feedback & Debug

Property	Description
Show Gizmos	Show AI state gizmos in the editor Scene view.
AI Color	Color for AI controlled agents visualization.
Debug Logs	Enable debug logging for AI decisions in the Console.

---

Public API

Properties

// Get current AI state
RTSAIState state = ai.CurrentState;

// Get agent counts
int controlledCount = ai.ControlledAgentCount;
int enemyCount = ai.EnemyAgentCount;

// Get difficulty level as enum
RTSAIDifficulty diff = ai.DifficultyLevel;

// Get AoE avoidance state
float threatLevel = ai.CurrentAoEThreatLevel;  // 0-1
float spacing = ai.CurrentFormationSpacing;    // Current spacing value

Manual Control Methods

/// Force the AI to attack immediately
ai.ForceAttack();

/// Force the AI to retreat
ai.ForceRetreat();

/// Force the AI to regroup its forces
ai.ForceRegroup();

/// Set combat stance for all controlled agents
ai.SetStance(CombatStance.Defensive);
ai.SetStance(CombatStance.Offensive);
ai.SetStance(CombatStance.HoldPosition);

AoE Avoidance Control

/// Get recommended spacing (respects AoE avoidance state)
float spacing = ai.GetRecommendedSpacing();

/// Manually set AoE threat level (0-1)
/// Useful for scripted events where you know AoE is coming
ai.SetAoEThreatLevel(0.8f);

/// Force immediate spacing update (skips smooth transition)
ai.ForceSpacingUpdate();

---

Tactical Behaviors

Baiting Tactic

When the AI has sufficient forces and tactical conditions are favorable:

1. Selection – AI selects a small percentage of agents as "bait"

2. Trap Setup – Main force moves to an ambush position behind the army center

3. Luring – Bait units approach enemies aggressively

4. Springing – When enemies pursue bait to the trap position, main force engages

// Conditions for baiting:
// - enableAdvancedTactics = true
// - Controlled agents >= minAgentsForBaiting
// - Random chance based on difficulty and force ratio

Retreat Logic

The AI retreats when significantly outnumbered:

// Retreat condition:
float forceRatio = controlledAgents / enemyAgents;
bool shouldRetreat = forceRatio < (1.0f / retreatRatio);

// Example with retreatRatio = 2.5:
// - 100 AI vs 250 enemies → forceRatio = 0.4 < 0.4 → RETREAT
// - 100 AI vs 200 enemies → forceRatio = 0.5 > 0.4 → STAY

Regrouping

Forces are considered "scattered" when more than 30% of agents are beyond regroupDistance from the army center. The AI will pause offensive actions to consolidate before continuing.

---

Integration Examples

Difficulty Scaling Based on Player Performance

public class AdaptiveDifficulty : MonoBehaviour
{
    public EnemyMassesRTSAI rtsAI;
    public int playerKills;
    public int aiKills;

    void Update()
    {
        // Increase AI difficulty if player is dominating
        float ratio = (float)playerKills / Mathf.Max(1, aiKills);
        
        if (ratio > 3f)
            rtsAI.difficulty = 5; // Nightmare
        else if (ratio > 2f)
            rtsAI.difficulty = 4; // Expert
        else if (ratio > 1.5f)
            rtsAI.difficulty = 3; // Hard
        else
            rtsAI.difficulty = 2; // Normal
    }
}

Scripted AoE Warning

public class ArtilleryStrike : MonoBehaviour
{
    public EnemyMassesRTSAI rtsAI;

    public void OnArtilleryIncoming()
    {
        // Warn AI of incoming AoE attack
        rtsAI.SetAoEThreatLevel(1.0f);
        
        // AI will automatically spread formations
    }

    public void OnArtilleryClear()
    {
        // Reset to auto-detection
        rtsAI.SetAoEThreatLevel(0f);
    }
}

Wave-Based Spawning Controller

public class WaveController : MonoBehaviour
{
    public EnemyMassesRTSAI rtsAI;
    public int waveNumber = 1;

    public void StartWave()
    {
        // Scale AI army size with wave number
        rtsAI.maxAgentCount = 50 + (waveNumber * 25);
        rtsAI.spawnWaveSize = 10 + (waveNumber * 5);
        rtsAI.enableSpawning = true;
        
        // Increase difficulty every 3 waves
        rtsAI.difficulty = Mathf.Min(5, waveNumber / 3);
        
        // Force initial attack
        rtsAI.ForceAttack();
    }
}

---

Performance Considerations

Setting	Impact	Recommendation
Decision Interval	Lower = more CPU	Use 0.5s for most games, 0.2s for competitive
Max Agents Per Decision	Batched processing	Internal limit of 100 agents per frame
AoE Detection	1 second cache	Negligible impact
Debug Logs	Console overhead	Disable in production

---

Gizmo Visualization

When Show Gizmos is enabled, the Scene view displays:

Gizmo	Color	Meaning
State Sphere	Varies	Current AI state at controller position
Army Center	AI Color (orange)	Center of controlled forces
Exploration Radius	Green	Current exploration area
Trap Position	Red	Ambush location during baiting

State Colors

State	Color
Idle	Gray
Exploring	Green
Engaging	Red
Retreating	Yellow
Regrouping	Cyan
SettingTrap	Orange
Baiting	Magenta

---

Troubleshooting

AI Not Controlling Any Agents

1. Verify Controlled Factions includes your AI faction names

2. Ensure agents exist in the scene with matching faction names

3. Check that agents are not dead (isDead = false)

AI Not Attacking

1. Check Enemy Factions configuration or enable Auto Detect Enemy Factions

2. Verify Player RTS Controller reference is set (for auto-detect)

3. Ensure enemy agents are within Engagement Range

AI Retreats Too Often

• Increase Retreat Ratio (higher = less likely to retreat)

• Ensure your AI faction has enough spawned agents

Formations Not Spreading for AoE

1. Enable Enable AoE Avoidance

2. Check that enemy factions have enableAOE configured in their ProjectileConfig

3. Verify AoE Threshold Radius isn't set too high

4. Try manually setting threat level with SetAoEThreatLevel()

Performance Issues with Large Armies

• Increase Decision Interval to 1.0s or higher

• Reduce Spawn Wave Size

• Disable Debug Logs

---

See Also

• Public API Reference – Complete API documentation

• RTS World Anchor System – Fog of war and minimap integration

• Networking Overview – Multiplayer synchronization