Glad you like it!

Just had another thought pursuant to the 'trickster god' angle:
In a later adventure, maybe they meet the god, who shows them that he has a ring on every finger except the one where the duplicating ring goes, and offers to trade them any one of his other rings for the one they have. Describe the appearance of the rings but don't tell what they do; just point out that a magic ring wielded by a god must be pretty cool. The trickster's rings can't be magically examined to discover their purpose; someone has to put it on and try it. Each ring will do something different, like:

- a diamond-encrusted ring, weighing nearly half a pound, but in obvious need of a cleaning: any time you need money for anything, this ring puts enough money in your pocket. It also gives you a near-fatal allergy to soap or anything that you'd use to clean yourself (you can use a brush on your horse, but if you try to use it on your own hair something very nasty happens). The ring can only be put on once by each person; once you take it off you can never touch it again.

- a wooden ring with small iron bands around it: this ring allows the wearer to subjugate animals and some nature spirits, but its magic is painful to the enslaved and whenever the wearer loses control he'd better be ready to be attacked by his former thrall. Cunning animals and spirits might even memorize your face or scent and hunt you. It would be a bad idea, for instance, to enslave the alpha of a wolf pack & then lose control of him

- a ring made of fused chain links: similar to the previous one, but it allows you to enslave anyone of a similar race (e.g. a half-orc could enslave an orc, a human, or a half-orc). When you lose control, your former slave gains control of you for half as long as you had him enslaved. Here's where the questions 'does he know he's under outside control?' and 'what did I make him do?' become important
*EDIT: If your slave dies under the ring's influence, the wearer still loses control of himself for the allotted time, passing out and appearing dead to all but a really good healer. Hope they don't bury you before your wake up!*

- a solid sapphire ring with trapped air bubbles: allows the wearer to breathe underwater and eat anything edible to fish. The longer this ring is worn, the more fish-like the wearer becomes until he is unable to survive out of the water.

- a ring of granite: this ring provides the wearer with invisible but heavy armor that takes damage like a stone wall would. the strength of the armor depends on the crowd, because it drains away some of the defense from each other person in the area. When this ring is taken off or destroyed, the wearer's body (starting at the extremities) begins to calcify, slowly turning into stone over the next months or years. *EDIT: and not 'The Thing' flexible stone; normal non magical solid stone. I guess as long as you can swing your stone arm, you can still shout "It's clobberin' time!" if you really want to...*

- a glass ring with eyes etched all around: this ring lets the wearer see in every direction at once. The downside is that you can't easily tell which way you're facing, which could be anything from inconvenient to fatal.

- a boiled leather thrumbring: doubles the accuracy of the wearer's ranged attacks (whether they're arrow, spell, whatever). The ring also doubles the damage of ranged attacks made against the wearer.

that's all I've got at the moment; if I think of anything else, I'll post it.

Or tell me to shut up, that's fine too