This will be an ongoing, though not necessarily consistent, series where I make up four random, and hopefully unique magic objects and devices each entry. These aren't things made for D&D 3 and up however, so it's up to those that do to come up with item prices and such. These things will also usually be quite vague, and are intended by the DM/GM/Ref/ML or whatever to make their own lore and reasoning behind the existence of these things.
Now for our first fun four.
A small gold band with a faint green sheen. When worn for more than 5 minutes, any sweat from the wearer leaves a thin, dark smudge where the ring had sat. While worn by its owner, the ring implants a firm feeling of self belief and general courage, treating their hit die as being one type greater than their current. This effect raises their maximum hit points by the difference per level, and drops it by the same number if removed. The "replacement" hit die is not used when rolling new HP during a level-up. If taken from the wearer in a most untimely manner, that the character will die if their hit points drop to '0' or less. For example, a 2nd level human fighter with d8 hit die with 14 HP counts as having a d10 hit die with 18 HP for the duration.
(This ring plays to the concept that HP represents the ability to avoid damage, as opposed to a measure of physical damage threshold)
Garb once used in an ancient dancing tradition, and usually danced to the breaking point. This pair, apparently wasn't. While worn, the user feels an uplifting feeling, encouraging extraneous dancing whenever in the presence of polka (or other very happy tunes). Even when not in the presence of chippy muzak, the wearer may lightly hop about when in a good mood. Heroes gain the most use of these boots in any activity involving jumping, skipping and dodging. Dodge-ball was a main event in those ancient traditions. When jumping, the wearer can jump 10 feet farther than normal, horizontally and vertically; in combat, wearers can do zany maneuvers such as leaping attacks as bullywugs do, and are considered as +2 to DEX in combat only for the potential of increasing their armour class. It is up to the discretion of the DM when the cord of the bangles breaks, freeing both glass beads and magical powers.
Mask of Mouse
Little more than a rough-hewn mask of petrified wood, this simple design is spartan at best. If worn across the face of any more flat-faced hominid, they and the mask suddenly merge, transforming the wearer into a tiny rodent as fitting their personality, as polymorph with no save against, nor chance of system shock. The transformation is permanent for 30 minutes; after which time the wearer may "peel" the mask from their face, an action only a wearer could find possible, though they are not alerted to any feeling that it can be removed now. Every 6 hours that the mask is worn roll against system shock, with a further penalty of -10 each attempt. Failure permanently fuses the mask and wearer, turning both into any other individual of the chosen race, erasing any identity or memory of who they once were. Attempting to dispel or remove curse gives the wearer a save versus death or be obliterated, leaving the mask behind. Passing the save separates the mask and wearer, permanently reducing the victim's intelligence by 2, though fused victims become a rodent in man's body.
Idiot's Tablet (cursed)
Like a wax writing tablet, but of a jet pitch in appearance, with string-attached writing and erasing utensil. Those who come in possession of this tablet must make a save versus magic or become infatuated with the device. They will incessantly argue the object's worth at any mention of its being, even when they really are losing the argument, and will refuse to separate themselves from it. Driven far enough into anger, an owner will resort to lethal violence to stop anyone trying to remove them of, talk terribly of, or attempt to destroy the tablet.