The Second Rule of Dungeoncraft
Whenever you fill in a major piece of the campaign world, always devise at least one secret related to that piece.

Ever since I introduced the Second Rule of Dungeoncraft way back in Dragon Magazine 256, I've tried to stress the importance of keeping good secrets. It's difficult to imagine a successful D&D campaign without a whole web of interesting secrets at its heart. In most cases, a good campaign is like a good soap opera -- it's the twists, turns, and unexpected revelations that keep the audience interested. Giving your players the opportunity to unravel big mysteries can give them a real sense of accomplishment, while simultaneously adding a lot of personality and depth to your campaign world.

Sadly, creating really interesting secrets can be tricky. I receive a lot of requests for tips on creating and using secrets in the fan mail I read each month. Unfortunately, creating appropriate secrets is a lot like swimming or riding a bike -- written instructions aren't very useful; you have to learn by watching and doing.

After giving this topic some thought, I decided that the best way I can help is to present a bunch of sample secrets. Although it should be easy to fit the rough templates I'll provide directly into most campaigns, my real hope is that exposure to enough of these ideas will get your own creative juices flowing. Along the way, I'll briefly discuss the ideas I present and include a few notes on how such a secret might affect the campaign.

One general piece of advice to consider when creating secrets is to strive for the truly outrageous. In most cases, the more shocking the secret, the more effective it will prove in play. A tactic I sometimes employ is to introduce a fact or situation that seems impossible, then allow the players to uncover the information necessary to explain it. After the second or third time the players get to the bottom of such a mystery, you'll usually find that you've nicely peaked their sense of anticipation, insuring their interest in the game. (What's going to happen next, and how is he going to explain it this time?)

I've divided my examples into five simple categories: historical secrets, character secrets, divine secrets, geographical secrets, and just plain weird secrets. The first two kinds are covered this month.

Historical Secrets
Shocking revelations about the hidden past of your campaign world can provide plenty of entertaining opportunities. Generally, this sort of secret not only gives your players something interesting to explore, it also conveniently fleshes out the history of your game world and provides springboards for several interesting adventures to come. The very best historical secrets give your players an opportunity to directly interact with the most important events that shaped the history of the game world, allowing them to feel like an important part of that history themselves.

Historical secrets can also serve as a great way to introduce exposition about the politics of your campaign. Uncovering the hidden truths that lie behind the alliance of two great kingdoms, for instance, should give the players interesting insights into how they might break that alliance.

1. Return of the Long-Dead Hero
Perhaps one of the long-dead heroes of your game world isn't really dead after all. Since this sort of secret is an obvious staple of comic books and soap operas, it needs to be well executed in order to be effective and interesting. A great deal rests on the quality of the explanation -- how or why did the "dead" hero survive? Come up with a detailed or novel answer and you've just created a powerful secret.
My version might go something like this: I'll invent a famous king who waged war across an entire continent in order to unite all its peoples under a single benevolent rule. Ironically, it is believed that the king was killed by the last arrow shot during the final battle of the great campaign, just over thirty years ago. In truth, the king wasn't killed. After winning the final battle, he abandoned his armies and was never seen again. Confused by the king's sudden absence and fearful that their newly forged coalition would crumble in its wake, the king's advisors invented the story of his death and set about forging the new, united nation.
In reality, the king was concerned that his remarkable achievements were making him particularly susceptible to the dangerous sin of pride. In the end, he decided that taking up the throne after all his great military victories would constitute too many accomplishments for any one man. In order to "put himself back in his proper place," he resolved to abandon his armies shortly after his final victory and spend the rest of his life living as a humble beggar in his former capital city.
This secret might set you up for a series of adventures in which the players first discover that the king is still alive, then discover the king's whereabouts, and finally attempt to convince the king to return to his armies and lead them against a menace threatening the kingdom he created.

2. A Secret Debt to Evil
This is a secret about a powerful and prosperous nation that overcame great odds to defeat a malevolent rival almost a century earlier. Unknown to just about everyone, the triumph came at a great price. During the final battle against their rivals, the rulers of the prosperous nation found themselves in desperate circumstances, and they were forced to employ the aid of a powerful demon to insure victory. In return for its services, the demon is entitled to the first daughter born to the ruling family every second generation. For the past one hundred years, the ruling family has secretly paid this price, each time carefully inventing a cover story to explain away the sudden death or disappearance of the princess.
During the campaign, the players might get their first inkling of this secret when they notice a strange outbreak of evil across the countryside. Eventually, they'll uncover the truth about the ruling family and the source of the evil outbreak -- the current king is refusing to turn his daughter over to the demon, prompting the infernal creature to take revenge. In the end, of course, it's likely that the players will discover that the demon created the original conflict between the two nations as part of an elaborate plot to maneuver the royal family into accepting the pact. The second-generation daughters of this particular family have some mysterious value to the demon, nicely setting the stage for you to create yet another secret.

3. History Repeats Itself
This one is a bit stranger than the first two examples. Across the course of the campaign, the players will gradually glean more and more details about the past history of the setting. Once they've accumulated enough of these details, they'll start to realize that the history of the planet is one huge cycle that repeats itself according to a definitive pattern over and over again. For instance, maybe every 1,116 years two great nations go to war, the smaller of the two nations always wins after exactly 23,411 lives have been lost in the conflict, and exactly twelve years later, the victorious general always loses his life to unexpected treachery.
This secret is particularly valuable to the players because of the way they can use it to predict future events, allowing them to accomplish great things while simultaneously giving them the feeling that they are true "movers and shakers." It also nicely sets you up to create still more interesting secrets -- what is the exact significance of the historical pattern, and how did it come into being?

4. When is a King not a King?
Most D&D game worlds boast dynasties of great kings who have ruled wisely over a particular kingdom or empire for generations on end. Typically, the citizens of these kingdoms thank fortune that each successive generation always seems to produce a fitting heir who turns out to be as wise as all his ancestors.
Suppose, though, that the kings are not the real font of wisdom behind the kingdom and never have been.
Unknown to everyone, including the kings themselves, the king's hereditary sword has been secretly governing the affairs of state since the foundation of the kingdom many generations ago. The sword is intelligent and capable of subtly manipulating its wielders to insure just rule. Perhaps it even houses the intellect of the very first king, who had the sword forged because he couldn't stand the idea of giving up his kingdom after death.
There are a number of ways such a secret might become important during the campaign. If the sword is stolen, for instance, the whole kingdom might unravel until it can be returned. Another possibility is a newly-crowned king discovering the secret of the sword and deciding that he doesn't want to make use of its capabilities. After the king attempts to rid himself of the sword, the sword begins plotting his downfall and drifts from owner to owner, hoping to find someone who can depose the king.

Character Secrets
Secrets about characters -- both PCs and NPCs -- provide another set of possibilities rich with opportunity. The classic character secret is a surprise revelation about a character's past, though the true possibilities are nearly limitless. Character secrets are particularly useful for encouraging good roleplaying and prompting your players to examine their characters a bit more closely. Nothing adds depth to a character like a good secret, and deep characters enhance your campaign in all sorts of ways.

It's easiest to create secrets about NPCs since you completely control their backstories, mannerisms, and behaviors, but don't be afraid to occasionally create secrets about the PCs. After all, heroes who discover hidden details about their pasts are a staple of myth and legend. Of course, some players are likely to be more receptive to these "discoveries" than others. You'll occasionally encounter a player who likes to carefully control his characters and create every detail of the characters' histories himself. Fortunately, these folks are relatively rare and easy to spot. Your best bet is to avoid them altogether and save your secrets for a more appreciative audience.

1. The Unexpected Relationship
Even though this old chestnut has been parodied to death (thanks to Star Wars), it's still surprisingly effective. The bit, of course, is that one of the characters in the campaign is secretly related in some way to one of the other characters. Maybe an evil wizard turns out to be the long lost brother of one of the PCs, or an NPC beggar discovers that he is actually a member of the royal family and the rightful heir to a throne.
Because secrets such as these can be kind of goofy if incorrectly executed, it's important to get them right. First of all, such secrets are rarely effective unless a long period of time elapses between the point at which everyone meets the two characters in question and the instant the hidden relationship is uncovered. In other words, don't introduce a brand new NPC in an adventure and reveal that the NPC is actually a PC's mother by adventure's end. The revelation will be much more powerful if you delay it for several adventures to come. Give everyone a chance to get acquainted with the new character and a chance to think they know her before you spring your big surprise.
It's equally important to devise a clever explanation for why the relationship has remained a secret for so long. Silly plot devices like amnesia and "stolen by gypsies" generally won't cut it without lots of additional details to shore them up and make them interesting. A workable example might go something like this: Suppose you've decided that one of the PCs is secretly the son of the evil baron who serves as the master villain in your campaign. All his life, the PC has assumed that he is actually the son of the good baron who is a lifelong foe of the villain. This mystery is explained by a strange pact the two barons forged long ago. In a desperate attempt to keep the peace between their two armies, the barons decided to secretly swap sons -- each would raise the other's child, making it difficult for either baron to attack the other without risking harm to his own son. Although the pact served its purpose for many years, the whole scheme finally went awry when the biological son of the good baron was killed by the PC during a craven attempt to assassinate the good duke, his "father's" lifelong enemy. Over the years, both barons became very fond of their charges and grew to think of them as their own sons. The evil baron now blames the PC for the death of his adopted son and has sworn revenge.

2. I'm a Murderer?
This is a great surprise to pull on a good-aligned player character. Every now and then, the PC should receive strange looks and such until one day a group of inquisitors finally arrives to confront him. The inquisitors have been pursuing the PC for several months and claim to have eyewitness evidence that the PC committed some unimaginably horrible crime. The campaign then proceeds for a time like a crime novel, with the PC and his companions struggling to prove his innocence, but becoming frustrated at each turn. If you orchestrate things properly, the remaining PCs might even begin to doubt their friend themselves. Things finally take the ultimate turn for the worse when some sort of unassailable method of establishing guilt (possibly magical) proves that the PC did, in fact, commit the crime even though he has no memory of it.
From this point, there are a number of ways you might explain the discrepancy, most involving magical mind control or similar means. My own explanation might go something like this: The PC is not whom he believes to be and never has been. In fact, the PC is a highly trained assassin from a land notorious for producing the most skilled assassins in the world. After performing a particularly difficult mission (the crime he is accused of), the PC was forced to drink a magical potion to escape. This potion effectively made the PC an entirely different person, giving him new memories and a new alignment. Once he had quaffed the potion, it was possible for the PC to evade various magical spells (like detect evil) that might have prevented his escape from the target's home. Even if he was captured and magically compelled to tell the truth, the PC would have no incriminating memories. Naturally, part of the plan called for the assassin's colleagues to recapture him at some point and restore his old memories, but that never happened. In fact, maybe the PCs first get wind of this secret when they foil the assassins' seemingly mysterious attempts to recapture their old colleague.
Once the scheme is in motion, of course, the PC is in quite a pickle. As a consequence, maybe you should wait until all the PCs have gained a few experience levels before springing this little gem. That should give them plenty of options when they deal with the fallout.

That wraps up another installment. Join me here in thirty days for "I've Got a Secret, Part II."