Random & Area Targeting

Origins

Random Targeting and Area Targeting were developed and documented by the RoboWiki community as fallback strategies for unpredictable opponents.

Random Targeting and Area Targeting are two simple strategies for firing when an enemy is unpredictable or when more advanced targeting methods fail. Neither assumes the enemy moves in a predictable straight line—instead, they cover a zone or scatter shots probabilistically.

These approaches are sometimes overlooked as "too simple," but they serve important roles: as defensive mechanisms against adaptive enemies, as fallback aiming when no clear pattern exists, and as baseline comparisons for evaluating smarter guns.

Random Targeting: The Scatter Gun Approach

Random Targeting fires bullets in random directions within a spread cone or angular range. The idea is simple: if the enemy is unpredictable, spread bullets across possible positions.

When does it work?

Random targeting tends to help when:

• The enemy dodges unpredictably (or uses random movement itself).
• The bot lacks radar lock on the enemy or loses track frequently.
• The bot is in melee and needs to throw multiple shots to hit someone among many bots.
• The bot is a learning or testing bot that doesn't yet have targeting logic.

It tends to fail when:

• The enemy moves in a clear, predictable pattern (linear, circular, or wave surfing).
• The bot has limited firepower and wastes shots.
• The gun overheats from rapid, inefficient firing.

How it works

At fire time, pick a random angle offset from a reference direction (e.g., the enemy's last bearing or gun's current heading) and fire.

# Simple Random Targeting

referenceAngle = absoluteBearingToEnemy()  # or gun's current heading

# Spread within ±spread degrees
randomOffset = random(-spread, spread)
fireAngle = referenceAngle + randomOffset

setGunHeading(fireAngle)
fire()

For tighter spreads, confine offsets to a narrow range (e.g., ±10°). For wider spreads, allow offsets up to ±30° or more.

Key tuning parameter: spread angle

The spread angle controls how wide the scatter is:

• ±5°: Tight cluster; assumes the enemy is roughly in one direction but slightly dodging.
• ±15°: Moderate spread; covers movement to left/right within a sector.
• ±45°: Very wide scatter; covers most directions and relies on hitting by chance.

Area Targeting: The Zone Spray

Area Targeting fires at a predicted region where the enemy might be, based on its last known position and assumed movement range. Instead of firing at a single intercept point (as in Linear or Circular targeting), the bot fires multiple shots or a spray pattern to cover an area.

When does it work?

Area targeting helps when:

• The enemy's next position is uncertain but confined to a zone (e.g., the enemy will move within 150 units of its last position).
• The bot expects perpendicular movement but doesn't know the exact speed or direction.
• Multiple shots are fired; at least one is likely to hit a region.

How it works

Define a bounding box or circular zone around the enemy's predicted position, then fire shots scattered across that zone:

# Area Targeting: Fire a spray pattern

enemyX, enemyY = lastScannedPosition
maxMovement = maxEnemySpeed * turnsSinceLastScan + bufferZone

# Define a box or circle of likely positions
zoneX = enemyX ± maxMovement
zoneY = enemyY ± maxMovement

# Fire multiple shots across the zone
for shot in 1 to numShots:
    randomPointX = random(zoneX - maxMovement, zoneX + maxMovement)
    randomPointY = random(zoneY - maxMovement, zoneY + maxMovement)
    
    fireAngle = headingTo(myX, myY, randomPointX, randomPointY)
    setGunHeading(fireAngle)
    fire()

Parameters: zone size and shot count

Two parameters control effectiveness:

1. Zone size: How far the enemy might have moved since the last scan.

   • Smaller zones assume the enemy hasn't moved far (recent scan, slow enemy).
   • Larger zones hedge against long delays or fast enemies.
   • Formula: maxDistance = lastKnownEnemySpeed * turnsSinceLastScan + safetyBuffer

2. Number of shots: More shots increase hit probability but consume energy.

   • Single shot at the enemy's last position (inefficient).
   • 2–5 shots in a burst (moderate cost, reasonable hit rate).
   • 10+ shots (heavy spray; rarely practical due to cooling delays).

Comparison: Random vs. Area Targeting

Aspect	Random Targeting	Area Targeting
Aiming basis	Any reference direction + random offset	Predicted movement zone
Information needed	Gun heading or enemy bearing	Enemy position, speed, scan age
Shot pattern	Scattered around a direction	Clustered around a zone
Best for	Melee chaos, quick fallback	Direct engagement with uncertainty
Energy cost	Low (few shots)	Higher (spray pattern)
Hit probability	Low unless enemy is close	Moderate if zone estimate is good

Platform notes

Both strategies are platform-agnostic and rely only on basic trigonometry (headings and angles).

• Classic Robocode: Convert enemy bearing + distance into coordinates, then use heading-to-point helpers.
• Robocode Tank Royale: Scans provide coordinates directly; use calcHeadingTo(x, y) for angle calculations.

See Coordinates and Angles for platform-specific conventions.

Tips & Common Mistakes

Combine with radar

If the radar loses the enemy, Random Targeting lets the gun still fire defensively. Pair it with a spinning radar to keep the gun cool while maintaining some offense.

Don't waste energy

Random and Area Targeting consume bullets inefficiently. Use them as fallbacks, not primary tactics. A bot with Head-On or Linear Targeting as the default and Random Targeting only when targeting fails performs better than a bot that always uses Random.

Melee chaos

In melee battles, Area Targeting around the enemy's zone can be effective, but prioritize enemies within a close distance to avoid spraying wildly.

Hybrid approach

A practical bot might:

1. Try Linear or Circular Targeting if the enemy seems to have a steady heading.
2. Fall back to Random Targeting if the enemy is erratic or radar lock is lost.
3. Use Area Targeting if multiple enemies are clustered in a zone.

Illustration placeholder

Random and Area Targeting patterns compared: Random fires scattered shots around a reference direction, while Area Targeting fires a spray across a predicted movement zone.

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Summary

• Random Targeting is a fallback when the enemy is unpredictable; scatter shots around a reference direction.
• Area Targeting fires at a zone where the enemy might be based on movement estimates.
• Both are simple to implement and useful in specific scenarios (chaos, lost locks, unpredictable foes).
• Use them as supplements to smarter tactics, not replacements.
• Combine with good radar and energy management for best results.

Further Reading

• Area Targeting — RoboWiki (classic Robocode)
• Random Targeting — RoboWiki (classic Robocode)