From publisher blurb:
Avalon takes a common spell and provides you with a number of alterations and additions to add excitement and useful options for your next adventure. Each issue of Avalon Spell Books will focus on a new spell, discussing different versions of the spell, providing different components that can be used to alter the way the spell works, and even adding feats and new magical items linked to the spell in question.
This month we have Phantom of a Trap.
How much damage can a trap cause that does nothing?
This is the question that comes into mind when you start looking for a best placing of the Phantom Trap spell. The answer, of course, is in the trap’s surroundings. Distractions, misleading clues, and red herrings are all good only when there are other traps or creatures that can take advantage of them. Making intruders waste time, dispel magic spells, and use up other resources is perfectly fine if they are going to have an encounter where they could have put these valuable assets to better use. Used a bit of your Luck ability to improve an unexplainably failing Disable Device check? You might mourn when you need it a few rounds later.
While many dabblers in Spellcraft know that a lock or hinge can have a false trap, few expect the same from an arrow slit or a crossbeam. The variant spell components provided below can help one make a better surprise of this simple illusion.
Lastly, Phantom Traps and other diversions can be combined with real traps. While designing such encounters, one needs a bit longer preparation than normal, but it really pays off when you have intruders struggle with a false trap and a real one comes upon them undetected and unexpected. The “Sample Traps” section at the end of this Spell Book provides some examples of magical and mechanical combinations that increase chances of a real trap working properly rather than getting routinely disarmed by the first rogue that comes upon it.