Moonbrighten, A System-Agnostic Spell

Moonbrighten

Description:  A simple incantation that can only be spoken in the light of the moon.  Alternately, it can be cast upon a single silver coin or disc, no more than two inches across.  Most experienced casters can master the spell, although it's beyond mere apprentices.

Effects: Moonbrighten has two possible effects, depending on which casting option is chosen.  If cast on a suitable piece of silver, that object shines with the light of a full moon as seen on a clear night.  This illuminates as well as a mundane lantern without generating heat and cannot be extinguished (although it can be covered up, hiding the glow).  The light has the same effects as the actual full moon would for all purposes, including were creatures, certain fey, and magical writings that can only be read under moonlight.

If cast without using a silver focus under the light of the moon, that light will be multiplied threefold everywhere within one hundred paces of the caster.  Depending on the phase of the moon and intervening cloud cover the effect varies somewhat, but even the very smallest crescent will be as bright as a full moon under similar weather conditions, while a half moon is nearly as bright as day.  A full moon will be so bright its dazzlingly painful to look upon, and weres and similar creatures will not only be forced into their animal or hybrid forms, they receive a 25% bonus to any damage inflicted by them while taking 25% less damage from all sources except silver.  Other creatures with lunar associations may be driven into bouts of manic activity or seem to be drunken while under this augmented moonlight.  Depending on the nature and inclinations of such creatures they may either flee the zone of the spell or seek to remain in it, perhaps even abducting the caster to ensure they stay in the light as long as possible.

Both effects last until moonset or sunrise, whichever comes first.  The death of the caster has no effect unless their body is utterly destroyed.

Possible Origins: This magic almost certainly began as a prayer to one of the lunar deities, although which one varies from culture to culture.  It can be used by almost anyone capable of employing magic, either arcane or divine, the exceptions being those who've somehow earned the disfavor of such a deity and, surprisingly, any were creature.  The latter can learn the charm but attempting to speak it sears their tongue like licking silver and spoils the spell.

Complications:  Triggering were-creature transformations or attracting some fey creatures are the main risks, but flooding an area with brilliant moonlight may annoy people who are trying to sleep.  The enhanced light doesn't scatter or reflect beyond the bounds of the spell, so people beyond that area most likely won't notice it was cast.  The center of the spell effect isn't obvious, so people or creatures trying to locate the caster may have some hunting to do, especially if moving rapidly.

Toothsome Curse, A System-Agnostic Spell

Toothsome Curse

Description:  A brief but but potent incantation calling an unusual curse upon one creature within earshot.  As with many curses the caster may end the magic at will, usually in exchange for some service or payment by the victim or their allies.  Otherwise the spell persists for seven days and seven nights, or until stronger counter-magic dispels it.   

Effects:  The target of this spell must be able to hear (but not necessarily understand) the caster and may attempt to resist the curse when it is first laid upon them (in D&D save vs. spells, or a Will save).  For the duration of the curse the target exudes a wonderful but indescribable aroma that can be detected by human senses out to about 30 feet, and much farther for creatures with a better sense of smell.  Any creature that can perceive this odor will be aware that the target would make a supernaturally tasty meal.  There's no actual compulsion to act on this knowledge, but animals will generally try to devour (or at least gnaw on) the victim, and even intelligent entities may be sorely tempted to take a bite or at least a quick lick.

Creatures without a sense of smell (most constructs and elementals, many undead, some aberrations, etc.) are unaffected by the odor, although they can be so cursed themselves.  Concealing the odor is difficult as even the strongest perfumes will only drown it out 50% of the time (check every minute or so while within range) and once "scented" by a creature they'll be convinced of the victim's extreme palatability thereafter.  Strong winds and similar weather conditions may affect detection ranges.  The victim cannot perceive the magical scent itself, nor do they taste more appealing than normal to their own senses.

Possible Origins:  This quirky curse is often credited to Grandmother although it seems rather petty for an entity of her reputation.  It seems more likely that some hedge wizard or druid came up with it long, long ago.  The spell is little-known amongst urban spellcasters (where it tends to mostly attract vermin and the odd homophage) but fairly common among those who live more rural lifestyles (where more dangerous beasts like wolves, bears, and less natural monsters dwell). 

Complications:  Like many curses, the target may resort to violence to force the caster to end the spell early, although its relatively subtle effect may not make it immediately apparent that an actual curse has been laid.  Creatures attracted by the victim's scent are not under the control of the caster, and may endanger other beings nearby or even fight among each other to get at the curse's tasty target.

The curse does nothing to actually increase the nutritional value or edibility of the victim, which can produce some strange and possibly unintended results if cast upon, say, a fire elemental, acidic ooze, or iron golem.

If Grandmother did actually invent this curse, using it might attract her attention.  You might even get a shiny new tooth or some candy if you're lucky, although whether that luck is good or bad is unclear.

Design Commentary:  If you're playing a game that uses D&D-style magic, this spell should be about 2nd or 3rd level.  As curses go it's situationally quite dangerous but there are many work-arounds:  spend a week in relative isolation, avoid places where there are dangerous animals, watch out for people who start drooling in your presence, etc.  It's not generally as crippling as being struck blind or some of the other nasty traditional curses.