This is a unique and powerful non-artifact magic item, system-agnostic but written with 4e in mind. I was inspired to finish it considering the recent "Got Loot?" blogging festival, though this is something that has been incubating in my mind since at least last April. It is my attempt to bring a sort of Fortune Cards-like aesthetic into the game, without being overly intrusive, but also having consequences. It utilizes FUDGE dice, which are special six-sided dice which have two blank faces, two faces bearing a "-" and two faces bearing a "+". It was very influenced by the Deck of Many Things, among other things, and I'd hope that its implementation and manifestation could be relatively flexible to manage in-game. Players can come across individual dice, as with cards from the DoMT, or else the entire set, whichever would seem more appropriate within the story. The item, which is a set of four ivory dice inset with golden suns and silver moons, will appear to be just an ordinary, if valuable, set of dice for a game called Canicerre (can-i-sair). It will be common in the area of the world where the dice are found, but relatively rare elsewhere. I use a combination of locales from 4th edition (Bael Turath features in the story), but also a newly invented locale (the Alvastratian Empire), which I figure for story's sake existed in the same larger geographical area as Bael Turath, but perhaps pre-dating both it and Arkhosia. There is no reason why any or all of it could not be relocated to somewhere more familiar to Pathfinder fans, such as Varisia or Katapesh. I'm less familiar with Golarion and I write chiefly for 4e (being the fantasy RPG with which I am most familiar), so it becomes my "implicit" setting. Similarly I use Tieflings and Eladrin in the story text, but the storyteller himself is suspicious of those attributions. They could readily be renamed to something more appropriate.
The dice themselves should be presented, at first, as simple treasure. They are made of a valuable material (ivory), appear to be very well made and of high quality, and two sides are inset with gold, and two sides are inset with silver. It would be assumed that a reasonable player would see the value in these, at least as loot to sell for gold or silver back in town. Likewise, the location they are found in should be relatively unremarkable; maybe they spill out of an old boot that is carelessly knocked over while one of the PCs is looking for something else. Maybe they are simply set atop a table within a cave that had been at some point previously been occupied but currently seems abandoned. However, the true value of the dice only becomes apparent once the PCs attempt to sell them. When presented to a shopkeeper, especially if asked what they are for, the following monologue might occur. Alternately, if one of the characters is particularly well versed in local history, they may know the following already:
"It's an old Alvastratian game, it's called Canicerre; it's simple. Let me show you. There are four dice, they each have these symbols on them, right? The sun represents a positive turn of fortune, the moon a negative; yeah the Alvastratians were sun worshippers, what do you want? You put all four dice in a cup, and you shake it around. You try to get one die to pop out; a lot of pros get up to some pretty fancy shaking to make it happen and land where they want it to. The rest of the dice stay in the cup, and you quick turn it over and smack it down on the table so they're under the cup, still covered. Everybody bets on whether the overall outcome will be positive or negative, and then the cup is lifted. Positive and negative sides cancel each other out, blank sides don't have an influence one way or the other. If the outcome is neutral, everyone gets their money back. If it's moons, all the people who betted suns lose their money. If it's suns, all the people who betted moons lose their money, get it? It's split up evenly from all the losers to all the winners, so if you're betting on an unpopular outcome, you stand to win more money than if you go with everyone else on it. If everyone bets one way and the result is the other, the person rolling the dice gets it all; it's the only way they can win since they can't ordinarily take bets, and it doesn't happen very often, but when it does, oh man, it can be a lot of money. There was a saying back in the old days in Alvastratia, 'rich as a roller.'
"But these dice, these are special. You probably don't know what you have here. See, there's a legend about these dice. They say that there was a guy, a gambler, who lived in the port of Arkash. Arkash was in Bael Turath, so tradition says that he was a Tiefling. Makes sense to me, since everybody knows that Canicerre is a Tiefling game anyway... At least they're the ones who are always playing it anywhere they go. Anyway, there was a gambler, nobody knows his name any more. I guess it's not important. And this guy, he gambled on everything. It was just sort of his nature. He said that if he had something, it was his to lose. If someone else had something, it was his to win. And he was always fair. If he lost, he lost graciously and moved on, never held any grudges, never carried any superstitions or excess baggage along with it. Winning and losing, that was the only thing that mattered. He wasn't even known, so the stories go, for being particularly daring with his bets, I guess he just liked to leave everything up to fate or something. I don't know.
"But one day, as the story goes, he met a traveller. Now, a lot of people say it was an eladrin, but I don't know if that's so much that it was really an eladrin or if they just want some sort of trickster figure and eladrin fit but anyway, doesn't matter. This traveller is in town for a few days, watches the Gambler gambling on everything, finally approaches him. He pulls out these ancient, ancient looking Canicerre dice, inset with gold and silver, obviously well-worn but still in great shape, and says "I'll play you for these; they have a value far beyond anything you will ever possibly know." The Gambler, he's impressed by the dice, they're good looking, but he doesn't buy the yarn about any 'immeasurable value.' But a game's a game, so they go in to it. They drop in to a gambling house, the traveler hands a dealer there the dice. See it used to be polite if you were in a new town to at least make the gesture like you're contributing to the local economy, you know, give the dealer a chance to win, yadda yadda. Anyway, the dealer drops them in the cup, and the eladrin (or whoever) gestures to the Gambler, and says 'your call.'
"The dealer swirls the cup, pops a die out, it's the sun facing. Nevertheless, the Gambler says 'favor only shines at night.' See, there are a lot of traditions with the game; some people just say positive or negative, some people say suns and moons, this guy gussied up his calls with a little poetry, guess he did it so often he had to keep it interesting. Whatever. The eladrin (whatever) says 'suns' to give the opposite bid. You know, it's polite if you're playing one-on-one to pick opposing bids, otherwise there's a lot of stalemates going on. Also it's usually smart to pick the facing symbol anyway because the odds are a little in favor of what's already showing. The dealer nods, lifts the cup. There are two moons and a sun. Stalemate. Since they're not playing for money, the dealer sweeps up the dice and drops them in the cup. One pops out, it's a sun again. Yet again, the Gambler says 'dark as night, never bright.' The eladrin nods, and replies 'the sun will forever shine.' The dealer nods, lifts the cup. Again, it's two moons and a sun. Once again, the dealer scoops up the dice, pours them into the cup, and swirls it around. He pops a die, it shows a blank face. The eladrin says 'ah, intriguing! Why don't we raise the wager? If I win, I make one request, which you must abide by for the rest of your days. If you win, I remain here in your service, until I am discharged by your command.' The Gambler says, 'no sir, we began this game over these dice, and these dice are what I'm playing for. If you want to make other wagers, we'll resolve this one first and then we'll talk.' The eladrin nods and raises his hand to gesture that the Gambler make his bet. The Gambler says 'three moons hang alone in the sky, never to meet, never to die.'
"See this is another thing I forgot to tell you about the game. Sometimes people will make a wager based on what the exact configuration of the dice will be, and then they can win more of the pot than usual, but they weren't playing this game. I guess he was just making that bet for poetic purposes, it wouldn't have had any effect on the game one way or the other, just that he had wagered on 'moons' instead of 'suns.' The eladrin says 'three times three is a risky wager indeed!' Do you see where some people might think that this character might have been an eladrin, by the way? Who talks like that but them? Well, I suppose halflings do, but nobody wants to listen to a story about a mysterious halfling. Anyway, he says 'a three times three is a risky wager indeed!' I said that already, but there's a reason for that. You know, if you bet the same thing three times in a row, there's an old superstition that you'll always lose on your third time, but this Gambler, he wasn't swayed by any superstition, so he just says 'that's my wager, and I'm standing by it.' So the dealer lifts the cup, and sure enough, plain as anything, three moons are facing upwards. The eladrin stands up, pushes his chair back from the table, and says 'the dice are yours by your right, and they are parted from me duly. Good day, and good luck.' And he walks out. Nobody ever sees him again. Nobody sees him leave, like as soon as he walks through the door, he's gone. Course it was in Arkash and nobody sees anything in Arkash, at least not without the jingle of gold in their ears, so that's not really all that remarkable. A lot of people, they like to play up the mystery there in that part, like ooooh he was a ghost or something, but I've seen plenty of ghosts, and this doesn't sound like a ghost.
"Anyway that's just the beginning of the story. I could probably talk your ear off all day about this legend, s' popular with the kids and all (course some people add in lots of moral lessons like 'don't gamble' or more dubious ones like 'don't gamble with eladrin' or some such) but anyway, long story short is Gambler finds out that he got a lot more than what he bargained for. He'd only use these dice, you know, for special occasions. They were nice, you don't just sit out in the dusty street and roll ivory dice inlaid with gold and silver, but whatever, you know what I mean. But he came to realize that, not only did winning or losing with the dice seem to bring him bigger wins or losses, but the effect seemed to last for days. And now like I said, he was no superstitious man, but when weird things happen often enough, you start to think like something weird is going on. When he won with the dice, it was like he couldn't lose. He'd have streaks for days where everything he played, he played well. When he lost, he lost everything. Got to a point where the streaks scared 'im so much he all went up and almost quit gambling altogether. Didn't like the ramifications. Occasionally he'd try to offer the dice up as a prize, just like the eladrin did, to try to get rid of them. But he'd always win. No matter what he bet, the dice were always in his favor any time he tried to get rid of them. Started to think they were a curse, never used them. Gambling lost its flavor for him, these dice weighing down on him, never knowing whether they were actually cursed or magical or anything like that, or whether he was just getting old, and eventually he just up and disappeared, they found the dice on his table, four moons staring up at the ceiling, like he was there one minute and gone the next. Nobody ever saw him again, nobody claimed the dice as their rightful property, eventually the shopkeeper in town said he'd put 'em up for sale, use the money to pay for a gravestone (they just assumed if he wasn't coming back, he was probably dead), and that's where the story leaves off. Nobody knows what happened to the dice after they sold, but they say there's a plain gravestone standing in Arkash today, no name on it, just standing there like it's proof that someone was there. Where'd you say those turned up, again?"
The Gambler's Dice can be represented, in the real world, with a set of 4 FUDGE dice. The plus side represents the sun, the minus side represents the moon. The mechanics otherwise are exactly the same, each sun cancels each moon, and any left over beyond that denotes a winner. The large majority of games will result in a draw, and it is customary among most gamblers to either raise or withdraw their bets during these instances. Canicerre can be played in-game at any time, for gambling purposes or for a quick-and-dirty method of divination (will the immediate future be favorable or unfavorable? by what degree?). It is only with the Gambler's Dice that things get "dicey." Beyond their use as a gambling tool, they can also be used to influence fate. At any time, as a standard action, as a daily power, in or out of combat, the player in possession of the Gambler's Dice may roll the dice as long as there is a reasonable surface upon which to do so. The character does not need to be able to see the results of the dice, and the effect generated begins instantaneously. It is up to the GM to determine the effect of the outcome, but it should be in line with the overall "score" achieved by the roll. In other words, a roll that evens out to zero will probably not have any effect at all, +1 might make an attack that otherwise might have just missed hit, +2 might save the player from a status effect or an environmental mishap, +3 might drastically alter the strength of an opponent or the treasure encountered, and +4 will likely be some extremely unlikely, massive, and potentially game-changing event, like a god suddenly taking direct interest in the character and personally guiding their hand. Conversely, -1 might make the character's next action fail, or prevent them from achieving a critical hit on a natural 20, or something of the like, and so on. A -4 result will be catastrophic for the character. They may be pulled into a demiplane of suffering, they may be struck down where they stand by a freak accident, but the outcome should not only be dire for the character, but for the entire party. This result should also result in the dice being "lost" and unrecoverable by the party.
The Gambler's Dice are not an "evil" item, but they are chaotic in their function. It is unclear whether the dice were invented to be magical, or with any sort of magical purpose in mind, or whether they "developed" on their own. They do not function like an artifact; they do not possess any degree of "intelligence" and do not attempt to influence or direct their possessor's behavior. But nor are they a "good" item, for they do not always act in their holder's favor, letting instead the dice fall where they may, and then influence the world around them accordingly. Primarily any effect is negated every time the dice are re-rolled, but the dice roll has no effect one way or the other if attempted more than once in 24 hours. Otherwise, the effect will subside in 1d4 days, waning in influence over time. As a static magic item, they grant the possessor +1 Streetwise (or, for Pathfinder, Knowledge [local]) and -1 Diplomacy as long as they are somewhere in the vicinity of the person. For the purpose of this mechanic their "owner" is defined as the person who last touched them with their bare hands, although if that person should travel any appreciable distance away from the dice (such as leave town), "ownership" passes to any character who is nearest or currently in possession.
Beyond this, the significance, importance, and back story for the dice are entirely up to the Game Master, and entirely dependent upon their own campaign to let the mystery of the dice develop further (or not). Perhaps one of the PCs will decide to roll the dice when they are first found absentmindedly. If this occurs make note of the results, and have their influence (if any) be felt, but be unclear about whether it is the dice that are influencing how things have suddenly turned, or something else about where they are or what they are doing, then reveal it when they learn what the dice are.