These spells and items have played a prominent role in my various D&D campaigns over the years. They should be amendable to the various D&D editions available to all players, including retro games such as Labyrinth Lord and BlueHolme. I am uncertain about 4e or 5e as I do not play those sets... yet.
The first entry to the 52 Weeks of Magic is a basic magic spell employed in a way that was never really intended: Continual Light as magic item. Quite possibly, this was your first magic item. It was mine.
The spell creates a sphere of light with a 60' radius. It will move at the direction of the caster or it could be attached to a mobile or immobile object such as a rock. As an attack spell, it could be cast at a creature's eyes to cause blindness. Over the years, dispelling the globe of light was worded differently. It could be canceled by a Darkness spell, at will by the caster, Dispel Magic, and in the case of blinded creatures, Remove Curse.
Gee, that is a rather problematical spell on a couple of levels. It disappeared in 3.5e, replaced by Continual Flame which has a cost and is less effective. This was a stylistic change and probably for the better.
Down to the brass tacks. Or tube, as the case may be. Character's intelligent enough to realize the immediate benefit of the spell could cast this spell into a scroll tube. My character used a brass map tube, creating a brass lantern, ala Zork. One of my players cast the spell into a cut and blackened tube of bamboo and added a large glass bead for color and dubbed it the 'boo Torch. The color of the bead of glass was assigned to specific characters so they could identify each other over great distances. How ingenious.
This article is not about the spell, it's about the items created for the spell. The material cost can be very low in the case of the 'boo Torch. Or more likely, the spell would be cast on a high value item such as an ornate, custom-made tube or a standard votive candle.
The game breaking aspect of this spell and the items created by it are not the obvious ones. A Continual Flame spell in 3.5e carries a cost of 50 gp. Even at many times this rate, every village should have one or more lanterns powered by Continual Light. Dungeons should be lit all the time. Another consequence is lanterns should not exist at all or exist as a cheaper replacement to the magic lanterns being turned out by the player characters.
An interesting cultural twist on this type of item is whole cities being lit by these devices. Attackers would be well advised to make Dispel Magic and Darkness apart of their siege craft. Imagine the terror of having your defenses plunged into darkness the moment a besieging army arrived? Where are those lamps and torches, again? Defenders wouldn't have ready stocks of oil due to a lack of reliance on it for lighting.
Another aspect to considered for this infiltration of magic on a culture is the lack of heat by light sources. A permanently lit room is pretty chilly without a fire or stove. Some cities may require lamp and torch making materials on hand at all times after the "White Winter Death", a particular bad winter which exhausted all primary sources of fuel for heating and no reserve of burnable lighting materials existed. Sure, there was light but it was of little comfort from the cold. Other cities may not be able to handle tradition sources a light as they are walking fire hazards.
In general, if a culture has no reliance on oil for lighting, the need for oil is greatly reduced. This fact could reduce a nation's need for presses, ceramics, waxes, machines, crops like olives, the hunting for blubber bearing creatures, etc. Lighting is a critical aspect of a culture's style.
Limitations to this type of object could be simple. There is a desire to outdo other wizards, clerics and magic users by having the most ornate device imaginable. It isn't a material cost of the spell, it is the desire to have shinier kit than everyone else that drove the price.
Another limitation introduced by my characters was to voluntarily end the blinding effects after a period of time. This is an entirely different issue, but interesting because the players thought of it themselves. I liked it because I had forgotten about the poor blinded victim. He was never coming back into the story, but the good and lawful players decided that a day of blindness was more than enough "punishment". Can you say bonus role play experience?
The oddity of this was the "dispel at will" function never had a clear distance rule. This circles back to siegecraft, a wizard could be enticed to turn out the lights on an offending city.
I experimented with the "the birthday rule", where all magic spells ended on the caster's birthday if not supported by another energy source. A Resurrection spells continued past the birth date of the caster because the living person was the source of power for continuance, but poorly worded Wishes and Continual Light stopped on the caster's next birthday. I liked this story line as a one shot, as it put a single character at the center of an adventure, but it was impractical over time. This adventure corresponded to a player's birthday and I was unable to keep it going over the whole campaign.
I hope you enjoyed this essay. Next week's magic item is The Rat Bag. Please come back next Saturday evening for another unique essays on magic.
Week 1 of 52 - Magic Lamps
Week 2 of 52 - The Rat Bag
Week 3 of 52 - Emulous Cursed Sword
Week 4 of 52 - The Cloak of Peaceful Repose
Week 5 of 52 - The Cowl of Death
Week 6 of 52 - Scimitar of Smiting
Week 7 of 52 - The Symbol of Sol Invictus
Week 8 of 52 - The Equi Phalera
Week 9 of 52 - Libertatem
Week 10 of 52 - Sorrow
Week 11 of 52 - Aemilla Carna
Week 12 of 52 - The Obice Cardeam
Week 13 of 52 - The Gnollish Rattlebone
Now, the commercial. I have a little book called Zero to Hero: Uncommon Commoners, over at DrivethruRPG. I am obviously thinking of writing another and Gnolls might be the subject. Please let me know what you think in the comments.