Light

This spell creates a torch-like radiance that emerges from some object. Certain versions can also be used to blind the target, by casting it on their eyes, or by making the light spring from some point in space. Often, this spell is more ably used by clerics than by wizards, being usable at a greater range and for a longer duration. Clerics may also use the reverse of this spell, causing darkness instead of light. This use may or may not be from spells like darkness in that the latter spell often bars all vision (including darkvision or infravision), while a reversed light spell simply creates an absence of normal light.

The improved version of light is called continual light, and tends to shed brighter light for an unlimited duration.

Uses

The spell's primary use is to serve as illumination in the dark, replacing a torch with a glowing staff or stone. It's more versatile than a torch, but in the early editions, it used up a spell slot that might be better spent on other things, except at higher levels. As of 3e, the spell became "cheap" enough even for low-level casters that it was a common replacement for torches in the party, and 4e and 5e have continued this tradition, keeping the spell very efficient. This spell is often the go-to spell to brighten dark places in D&D.

The spell has also occasionally been used to make enemies more visible, causing them to shed light and thus making it difficult for them to hide or remain obscured in shadows, similar to faerie fire.

A third use of the spell, applying mostly during 2e, was its ability to blind creatures by being cast on the creature's "visual organs." This could make the spell a useful combat debuff as well as a handy tool for exploration.

Original D&D

Light

The spell appears on the Cleric and Magic-User lists in Men & Magic. Clerics get better results with the spell than magic-users. Illusionists can also use the spell when they are introduced in The Strategic Review 1-4, and cast it as a cleric. Illusionists can use the reverse of the spell, and Anti-clerics must use the reverse of this spell. Dragon Magazine #12 preserved this spell on the Illusionist list, at 1st level, but indicated that it was cast as a magic user, with the shorter duration. 

• Spell Level: 1 (cleric, illusionist, or magic-user)
• Duration 12 turns + 1 turn/level (cleric, illusionist) or 6 turns + 1 turn/level (magic-user)

Casts light -- not equal to daylight -- in a circle 3" in a diameter for the duration.

Reversed Form

The reversed form is not specifically described, though on the Illusionist's spell list, it is called "Darkness." Presumably, it creates darkness in the circle for the duration.

Continual Light

This higher-level version of the light spell persists long after it is cast, until it is actively dispelled. Dragon Magazine #12 preserved this spell on the Illusionist list, at 2nd level, but indicated that it was cast as a magic user, so is not the equal to daylight. The Illusionist gains access to the full-daylight version as a level 3 spell. Dragon Magazine #12 also indicated that illusionists could cast the reversed form, as a magic-user, as a level 2 spell, with the reversed form as a cleric cast as a level 3 spell.

• Spell Level 2 (cleric, magic-user, illusionist [as magic-user]) or 3 (illusionist [as cleric])
• Range: 12"

The continual light spell sheds light in a circle 24" in diameter. For clerics and illusionists, this light is equal to full daylight.

Reversed Form

The reversed form is not specifically described, though on the Illusionist's spell list, it is called "Continual Darkness." Presumably, it creates darkness in the circle permanently.

AD&D

Light

Debuted in the Player's Handbook as a cleric spell. It also appears as a magic-user spell. The Dungeon Master's Guide contains additional advice.

Cleric

Level: 1	School: Alteration
Components: V, S
Range: 12"	Casting Time: 1 round
Duration: 6 turns + 1 turn/level	Saving Throw: None
Effect: 2" radius globe

Excites molecules in the area, making them as luminous as a torch. The light springs from air, rock, metal, wood, or almost any other substance. The light can be made to spring from a creature, who is entitled to magic resistance and a saving throw to avoid the effect -- if the spell is resisted or saved against, the light springs from just behind the creature, rather than on the creature itself. The light created is equivalent to torchlight, but only within the area. The caster can utter a word to extinguish the light early.

DM Advice: If cast on or direclty in front of a creature's eyes, the light may blind it, as if a strong light were placed there. This causes a -4 penalty on attacks, saving throws, and armor class. The spell is not mobile, though the object or creature it is cast on may be moved, thus moving the spell. If the light is placed in some container, the light is effectively doused, blocked from spreading its effect.

Reversed

The reverse of the spell causes darkness in the same area, but only lasts for half as long.

Magic-User

Level: 1	School: Alteration
Components: V, S
Range: 6"	Casting Time: 1 segment
Duration: 1 turn/level	Saving Throw: None
Effect: 2" radius globe

Excites molecules in the area, making them as luminous as a torch. The light springs from air, rock, metal, wood, or almost any other substance. The light can be made to spring from a creature, who is entitled to magic resistance and a saving throw to avoid the effect -- if the spell is resisted or saved against, the light springs from just behind the creature, rather than on the creature itself. The light created is equivalent to torchlight, but only within the area. The caster can utter a word to extinguish the light early.

Magic-users cannot use the reverse form of the spell.

DM Advice: If cast on or direclty in front of a creature's eyes, the light may blind it, as if a strong light were placed there. This causes a -4 penalty on attacks, saving throws, and armor class. The spell is not mobile, though the object or creature it is cast on may be moved, thus moving the spell. If the light is placed in some container, the light is effectively doused, blocked from spreading its effect.

Continual Light

Debuted in the Player's Handbook as a cleric spell and a magic-user spell. The Dungeon Master's Guide contains additional advice.

Cleric

Level: 3	School: Alteration
Components: V, S
Range: 12"	Casting Time: 6 segments
Duration: Permanent	Saving Throw: None
Area: 6" radius globe

This higher-level version of the light spell persists long after it is cast, until it is actively dispelled. It creates a brighter, more powerful light upon the target, "nearly as illuminating as full daylight." The spell is noted to be able to blind creatures if cast on their visual organs.

DM Advice: If cast on or direclty in front of a creature's eyes, the light may blind it, as if a strong light were placed there. This causes a -4 penalty on attacks, saving throws, and armor class. The spell is not mobile, though the object or creature it is cast on may be moved, thus moving the spell. If the light is placed in some container, the light is effectively doused, blocked from spreading its effect.

Reversed

This spell creates a sphere consisting of the complete absence of light in the area that extends to the radius. Like it's alternate form, the spell can be cast on a creature, but the creature gets a saving throw and magic resistance.

Magic-User

Level: 2	School: Alteration
Components: V, S
Range: 6"	Casting Time: 2 segments
Duration: Permanent	Saving Throw: None
Area: 6" radius globe

This higher-level version of the light spell persists long after it is cast, until it is actively dispelled. It creates a brighter, more powerful light upon the target, "nearly as illuminating as full daylight." The spell is noted to be able to blind creatures if cast on their visual organs. Magic-users are incapable of reversing the spell.

AD&D 2e

This spell was used by clerics, druids, and wizards. It was also used by any specialty priests who could access the Sun domain, and any specialty wizards who were not barred from Alteration.

Light

• Spell Level 1 (priest, mage)
• School: Alteration / Spheres: Creation, Guardian, Sun
• Rarity: Common
• Components: Verbal, Material (a firefly or bit of phosphorescent moss) (mages) or Verbal, Somatic (priests)
• Casting Time: Standard Action (1 (mage) or 4 (priest))
• Range: 60 yards (mage) or 120 yards (priest)
• Duration: 1 turn/level (mage) or 1 hour + 1 turn/level (priest)
• Area: 20-ft. radius globe of light

This spell causes light to spring from a given location and spread out to the spell's area of effect. It is noted that the light can spring from any target, air, rock, metal, wood, or "almost any similar substance." The spell isn't mobile unless it is cast on an object that itself can be transported, and such an object can be hooded or placed in a box to block the light it sheds. The spell can be cast on a creature, though the creature is allowed a saving throw and magic resistance. Successful magic resistance negates the spell, and a successful save causes the spell to manifests in the space just behind the creature. The spell doesn't function in magical darkness, but can be cast specifically to dispel such darkness (though only momentarily if the darkness is continual).

The spell can be cast upon a creature's "visual organs" to blind it, reducing its saving throws, armor class, and attack rolls by 4. The creature receives magic resistance and a saving throw, with the former negating the effect and the latter causing the effect to happen just behind the target.

The spell can be cancelled by a darkness spell cast against it specifically, and can likewise cancel a darkness spell if cast against it.

Darkness

For evil priests, the spell is Reversible. When reversed, it is called darkness.

Note

The "sun" sphere does not appear in the spell's description, but the spell is included in the list of Sun-sphere spells, and Continual Light is listed in this sphere as well, so the sphere is included here.

> Continual Light

This higher-level version of the light spell persists long after it is cast, until it is actively dispelled.

• Spell Level 2 (mage) or 3 (priest)
• School: Alteration / Spheres: Creation, Guardian, Sun
• Rarity: Common
• Components: Verbal, Somatic
• Casting Time: Standard Action (2 (mage) or 6 (priest))
• Range: 60 yds. (mage) or 120 yds. (priest)
• Duration: Permanent
• Area: 60-ft radius globe of light

This spell's light is as bright as daylight (causing penalties for creatures that take penalties in full daylight). The light lasts until dispelled, or until negated by magical darkness. Like a normal light spell, it can be cast on an object (which can then be hooded or stored in a container to block the light), or on a creature's "visual organs" (causing blindness). If brought into an area of magical darkness, the darkness is negated for as long as the light is there, allowing natural lighting conditions to prevail.

The spell is noted as slowly consuming the material it is cast upon, but the timescale is more than a typical campaign. Hard and expensive materials might last for hundreds or thousands of years.

Continual Darkness

For evil priests, the spell is Reversible. When reversed, it is called continual darkness.

3e D&D

Spell Details

• Spell Level: Bard 0, Cleric 0, Druid 0, Sorcerer 0, Wizard 0
• School: Evocation [Light]
• Components: Verbal, Material (a firefly or a piece of phosphorescent moss.) (arcane) or Verbal, Divine Focus (divine)
• Casting Time: Standard Action
• Range: Touch
• Target: Touched object
• Duration: 10 minutes per level (D)

Description

This spell causes the object touched to shed bright light in a 20-ft. radius, and dim light for an additional 20 ft. It doesn't move, but the object shedding light can be moved, and the spell ceases to function in magical darkness. As a spell with the [Light] descriptor, it can counter or dispel a [Darkness] spell of equal or lower level.

Uses

This spell is normally used as a cheap, renewable substitute for torches.

Pathfinder

A caster can have only one light spell active at any one time -- casting this spell again dispels the previous light. If the spell is made permanent, it does not count against this limit.

In addition, the Pathfinder version of the spell allows Pathfinder classes Oracle, Inquisitor, Magus, Summoner, and Witch to access this spell.

4e D&D

Spell Details

• Wizard Utility
• Keywords: Arcane
• Casting Time: Minor Action
• Range 5
• Target: One object or unoccupied square.

Description

This spell's effect is to cause the target to shed light up to 4 squares (including the target's square). The caster can put out the light as a free action.

> Continual Light

Continual Light makes an appearance here as a Ritual.

• Level 2
• Price: 100 gp
• Category: Creation
• Components: 20 gp or 1 healing surge
• Time: 1 minute
• Duration: 24 hours

The ritual causes one target object to shed bright light in a 20-square radius for the duration. The caster or the creature holding the object can take a minor action to end the effect. The ritual can be cast from a scroll as a standard action that causes the object to shed light in a 5-square radius.

5e D&D

Spell Details

• Spell Level Cantrip
• School: Evocation
• Components: Verbal, Material (a firefly or bit of phosphorescent moss) (mages)
• Duration: 1 hour

Description

The caster touches an object up to 10 feet in any dimension, causing it to spread bright light (in any color you choose) in a 20-ft. radius and dim light for an additional 20 ft. You can spend your action to dismiss it. If you target an object held or worn by a hostile creature, the creature gets a Dex save to avoid the spell.

Spells with the [Light] descriptor: (0): Light, Dancing Lights; (1st): Color Spray; (2nd): Continual Flame; (3rd:) Daylight; (6th:) Sunbeam; (8th:) Sunburst; (9th:) Truelight* (New spell, as of 1496 DR see below):

Truelight

9^th Level Evocation [Light]

Casting Time: 1 Action

Range: 120 Feet

Components: V, S, M (Diamond or Sunstone worth at least 100 gp; if the gem is worth at least 10,000 gp, the spell becomes permanent and immobile.)

Duration: Concentration, up to 10 minutes

You conjure arcane true sunlight, no matter what the environment, even if it is magical darkness of 9^th Level.  A globe of pure white, blue-white or golden sunlight (your choice of color) appears in the palms of both your hands and emits blinding, brilliant light for 120 feet, torchlight brilliance for another 120 feet, and dim light (candlelight brilliance sufficient to read by) for yet another 120 feet.

·         All vampires and shadow creatures are immediately destroyed (no saving throw) and cannot be resurrected except by casting Wish or Miracle, and then rolling 19-20 on a d20.

·         All drow, duergar, and other denizens of the Underdark with superior darkvision are permanently blinded, Dexterity saving throw to regain eyesight in 1d3 days. (Blind creatures are unaffected by this effect of the magic.)

·         All plantlike creatures sensitive to sunlight instantly die.

·         If directed in a concentrated beam against a specific target, you get 1d4 rays, with ranged touch attack for each ray.  Each target hit takes 4d20+12 Radiant Damage, Dexterity Saving throw for half.

In addition, this spell dispels all invisibility and other illusions, and acts as a Gem of True Seeing  for the duration of the Spell.

Sources

OD&D: Men and Magic

1e: Player's Handbook

2e:

• Wizard's Spell Compendium Volume 2, pg. 515 (light);
• Priest's Spell Compendium Volume 2, pg. 374 (light)
• Wizard's Spell Compenidum Volume 1, pg. 175 (continual light)
• Priest's Spell Compendium, Volume 1, pg. 143 (continual light)

3e: http://www.d20srd.org/srd/spells/light.htm

PF: http://www.d20pfsrd.com/magic/all-spells/l/light

4e: http://www.wizards.com/dndinsider/compendium/power.aspx?id=1225

5e: Player's Handbook