Spell Index

Magic Sensor

Surveillance and alarms

Divination
Action: Standard
Components: V,S,M
Duration: See text
Spell Lists: Arcane,Divine
Levels: 1,3,5,7

The caster conjures a magical sensor that is a replica of their own sensory organs, possessing the same visual, auditory, and olfactory capabilities as the caster. This magical sensor aids in gathering information about entire areas and possesses additional enhanced capabilities including tactile feedback and specialized detection abilities.

If the sensor is used to observe an illusion or an invisible creature, the caster viewing through it must make a Will saving throw to see through the deception.

Spell Levels

Level 1

• Effect: Creates a stationary physical sensor that can rotate 360 degrees.
• Sensory Link: The caster can switch their senses to those of the sensor by concentrating.
• Base Capabilities: Replicates the caster's own visual, auditory, and olfactory senses.
• Enhanced Capabilities:
  • Can see through smoke and detect heat signatures.
  • Can function underwater and detect currents or water sources.
• Tactile Feedback: Can feel textures and temperatures through the magical sensor.
• Sensory Filter: Can filter specific stimuli (1 filter per point of Intelligence).
• Duration: Days equal to caster level
• Casting Range: Close (30 ft + 5 ft per caster level)
• Durability: 5 hp per level, 0 AC

Level 3

• Effect: Creates an invisible sensor that can move at a speed of 5 ft per tick.
• Multiple Sensors: Can observe through multiple sensors simultaneously (1 sensor per point of Intelligence).
• Enhanced Capabilities: All Level 1 capabilities, plus:
  • Can detect vibrations through solid surfaces, sensing movement.
• Detect Magic: Can cast Detect Magic through the sensor.
• Communication: Allows two-way communication through the sensor.
• Duration: Days equal to caster level
• Casting Range: Medium (100 ft + 10 ft per caster level)
• Durability: 10 hp per level, 20 AC
• Alarm Capability: Sensory Filters can send a sound alarm to the caster when specific conditions are met. Alarms can be programmed with multiple conditions, such as:
  • Send an alarm when:
    • A creature of size Large has entered the surveillance zone.
    • The creature looks like an Owlbear.
    • The creature smells like an Owlbear.

Level 5

• Effect: Creates an invisible sensor that can move at a speed of 30 ft per tick.
• Enhanced Observation: Can observe through multiple sensors simultaneously without concentration, at any time during the day (1 sensor per point of Intelligence).
• Enhanced Capabilities: All previous capabilities.
• Recording Capability: Can record observations for later review. Outputting recorded memories to a stone costs 10gp per magic sensor in enchantment costs.
• Duration: Days equal to caster level
• Casting Range: Long (400 ft + 40 ft per caster level)
• Durability: 20 hp per level, 40 AC
• Enhanced Alarm: Sensory Filters can send a mental alarm to the caster or a designated friend of the caster when specific conditions are met.

Level 7

• Effect: Creates an invisible sensor that can move at a speed of 60 ft per tick.
• Enhanced Observation: Can observe through multiple sensors simultaneously without concentration, at any time during the day (2 sensors per point of Intelligence).
• Enhanced Capabilities: All previous capabilities, plus:
  • Permanent Detect Magic: Each sensor has a permanent Detect Magic spell active.
  • Advanced Alarm System: Sensor Filters can send mental alarms based on complex magical conditions.
• Alarm Examples: Send an alarm when:
  • A creature of size medium has appeared.
  • It looks human.
  • Detect Magic indicates that the creature has a strong magical aura, similar to the caster's.
• Recording Capability: Can record observations for later review. Outputting recorded memories to a stone costs 5gp per magic sensor in enchantment costs (reduced from Level 5).
• Duration: Weeks equal to caster level
• Casting Range: Extreme (1 mile + 100 ft per caster level)
• Durability: 40 hp per level, 60 AC

Countering Magic Sensors

• Level 1 Sensors: Being visible, they can be directly attacked and destroyed.
• Level 3 and 5 Sensors: Being invisible, creatures must first succeed on a Will save against the spell's DC to perceive the sensor. Once perceived, the sensor can be attacked.
• All Levels: Dispel magic and similar abjuration spells can counter the sensors, requiring an appropriate caster level check.

Examples

Sensory Filter Example

A wizard with a +3 Intelligence modifier casts a Level 1 Magic Sensor. With 3 sensory filters available, they could:

1. Filter out background noise to focus on a specific conversation.
2. Isolate a particular scent to track a creature.
3. Focus visual perception on movement, ignoring stationary objects.

This allows the wizard to gather precise information in complex environments.

Sensor Placement Example

A rogue casts a Level 1 Magic Sensor and wants to observe a guarded room. After casting, they carefully throw the lightweight sensor through a small window. The sensor, being durable and light, survives the throw and lands inside the room, providing a perfect vantage point for reconnaissance.