5e’s d100 starting trinkets are all very well, but after a few campaigns, you’re guaranteed to roll repeats. I don’t want too many characters starting with a “small, weightless stone block” or whatever.

It would be great to have a backup list of mysterious trinkets, so you could Cross Out and Write In as you used ’em. I’ll start; leave more in the comments.

A tattoo that specifies the time and place of an unknown future appointment.
A padlock that can be opened by all keys except the one it comes with.
An architectural schematic of a vast baby.
A botany book filled with dangerous misinformation.
An order for your own execution.
A wooden coin on which is written a curse.
A membership card to an exclusive club.
A list of six names, including yours, with three crossed out.
An obsidian figure of a panther; it has absolutely no magic powers.
A map with several strange inaccuracies.
A badge from a forbidden order of fallen paladins.
A doll-sized sword of masterwork quality, useful as a razorblade.
A tiny scroll bearing nine unusual names.
The deed to a house in an underwater city.
The recipe for a Potion of Deafness.
A dragonchess piece with a hidden compartment: inside is a human fingerbone.
A flute; its out-of-tune notes can play no known song.
A moss-covered book written in Druidic characters.
A green copper tool with no obvious function.
A piece of amber containing an insect; the insect wears a tiny saddle and halter.

Let’s assume that all PC backgrounds and traits are assigned randomly (there are 13 backgrounds so about 7.5% of PCs have each background).

Out of every 1000 Player Characters:
15 are fire eaters. (d10 entertainer routines, of which you get 1d3) Makes sense that this number is so high, since every bad fantasy movie has at least one fire eater per crowd scene. Fire eating is apparently riveting entertainment in Fantasy Europe.
10 are librarians. (d8 sage specialty)
10 are blackmailers. (d8 criminal specialty) Blackmailers are not the most dashing of outlaws, and it’s hard to reconcile them with heroic fantasy. Nevertheless, I’m looking forward to many D&D adventures inspired by the life of Charles Augustus Howell..
A whopping 19 are raised by wolves. (d8 outlander personality trait, of which you get two)
4 are guild blacksmiths. (d20 guild business) This might sound naiive, but I absurdly thought that a smith background would be MORE common among adventurers than a raised-by-wolves background. Obviously I was off by a factor of 5. That’s why “Smith” is such a rare last name and “Wolfson” is so common.

Mike Shea has an interesting article about running mystery/investigation games. Running a mystery game is famously difficult, and Mike has a lot of great advice: don’t kill player involvement by dead-ending all their efforts. Don’t slavishly follow the letter of the module. Don’t bury the clues. And finally, change the mystery as needed.

If PCs seem to be spending all of their time in one line of investigation while the real answer lies somewhere completely different, we are well within our power and authority to move the clues. … Maybe NPCs begin to learn things they hadn’t known or the map is hidden in a completely different part of the mansion after all.

This last piece of DM advice is something which I’ve done many times before, and which makes total sense to me as a DM, but I’d like to add a note of caution as a player.

For a DM, it’s just good sense to rewrite the story; the players need never know, and everyone ends up having a better time. But as a player, I find myself quixotically kicking against this kind of good sense. As a player, I don’t want to solve a mystery because the DM moved the clues under my nose. On the other hand, I don’t want to waste a lot of time because the DM put the clues in the wrong place, either.

Here’s the thing: from my player’s perspective, sometimes it’s OK to move the clues and sometimes it’s not. Here’s my advice as a D&D player to DMs running mystery games:

Don’t let us players rewrite the mystery – unless our version is better

Even though you as the DM are constantly making up bits of the world for us, you are still capable of feeling suspension of disbelief yourself – and that’s important to maintain. At its best, DMing feels like channeling a world with a reality of its own. If the murder took place in the conservatory, it took place in the conservatory, even if we’re wasting our time investigating the billiard room – because, even though this statement sounds insane, “that’s how it really happened.” Once you’ve fixed something into the history of your game world, don’t excise it lightly. As a player, I want the game world to have reality and weight to it. I want to make some good choices and some bad choices, and look back with hindsight and know the difference. As a player, I want to take your world seriously, so make sure you do too.

There’s an exception to the “no rewrites” rule: one of us players might have a theory, or you might later come up with an idea, that’s better than your original plan. Now’s the time to rewrite history! The murder took place in the billiard room after all, because it makes more sense that way! Maybe I reminded you that Lord Wolfson loves to play billiards, so, now that you think of it, the billiards room would be a more logical place for the deadly confrontation. Retcon your story and change your plot, not for our convenience but because, now that you think of it, “that’s how it really happened.”

Honor our important choices, not our unimportant ones

Over the course of an investigation, PCs make a lot of significant choices. We might decide that the butler is on our side, and anyone who disagrees with the butler’s testimony is clearly lying. We might gamble on a risky Intimidation attempt, which might anger a key suspect or elicit new clues. The paladin might even decide that it’s dishonorable to read a gentleman’s letters, and burn a lot of key evidence unread. As a DM, you should honor those big choices, even if they make the investigation much easier or harder than you expected.

On the other hand, we also make a lot of insignificant choices. If you ask us which guest bedroom we are searching, we might say, “Uuh… the first one.” We might never visit the greenhouse because you forgot to mention to us that there’s a greenhouse. These are non-choices. Feel free to move the clue from the third to the first guest bedroom, or from the greenhouse to the ballroom.

Don’t figure out all the details beforehand

Let’s say the manor has 20 rooms and there are three important clues. Do we poor players really have to grind our way through a search of up to 17 meaningless rooms before we find a clue?

Here’s a reality-bending trick that doesn’t get my player hackles up:

Leave a lot of investigation details vague. Maybe you’ve decided that the chambermaid has a clue. You don’t need to key the chambermaid on the map. She might be in the second room we investigate, or the first, according to the dictates of pacing.

Maybe you haven’t thought at all about what’s in the stables, or what’s in town. If we investigate the stables, or start interrogating every shop owner in town, you as DM have carte blanche to make up clues: the more clues the better. It’s fine that these clues didn’t exist until we looked for them, because you’re not rewriting the mystery for us; you’re just filling in blank spaces in the map. That’s exactly what we expect from our DM.

So our group decides to search the stables, for which you prepared nothing. OK, you think, what’s in the stables? Let’s see, the victim arrived at the manor last night, so it makes sense that there’s an extra horse in the stables. And the stablehand would have seen the victim, and fed the horse. What’s in the saddlebags? Maybe a letter from Lord Wolfson to the victim? Maybe you roll a die to see whether that letter exists. Go ahead, you’re the DM.

What’s in town? Maybe we notice that the inn is called “The Wolf’s Arms.” “That must have some connection to Lord Wolfson,” I say, and we start coming up with a theory implicating the landlord. But the landlord wasn’t involved, and you as DM don’t need to retroactively involve him. Sometimes we’ll hit dead ends, and that’s OK.

provide interesting dead ends

Just as not every dead end in a dungeon has a secret door, not every area in an investigation yields a clue. Sometimes there are areas that don’t further the investigation.

But remember, you’re the DM of a living world, not just a mystery puzzle. Every area in the world can be interesting, even the places that have nothing to do with the mystery.

If you’re running a one-shot and trying to shepherd it to its conclusion by 10 PM, you might just want to say “You investigate the Wolf’s Arms Inn and find nothing to connect it to the murder.” But if you’re running a long-term campaign with no time pressure, then offer us a chance at some interesting new decisions: a fight, a quest – even a new mystery. Hey, we might find the second mystery more engaging than the first.

This might seem like a lot of improv pressure at the game table. After spending hours developing a mystery adventure, you’re supposed to come up with a new mystery, on the spot, in the, what, thirty seconds you have to think while we chatter about our crackpot innkeeper-did-it theory? Well, keep in mind you don’t need to come up with a solution to a new mystery right away, just a premise. And don’t worry, thirty seconds should be plenty of time.

To test this theory, I brought up the stopwatch feature on my phone. Let’s say the PCs start poking around in the Wolf’s Arms inn, which you haven’t prepared at all. I’m giving myself 30 seconds to come up with and develop a new tavern-based mystery as far as I can. At the end of the 30 seconds, I’ll write down what I come up with. I’ll try to do this four or five times.

The innkeeper doesn’t know anything about the murder, but….. three, two, one, go!

This never comes up in D&D gameplay, but I have a theory that most D&D games take place under a sun that’s dimmer and more orange than ours.

This has to do with D&D’s place in the Dying Earth sci-fi genre. D&D was largely inspired by Jack Vance, especially the Dying Earth stories, in which a far-future Earth lived its last days under a dying red sun. In this world, civilizations had risen and fallen millions of times, and there were ruins everywhere you looked.

For contrast, look at our world. Spinning along merrily under a young yellow sun is our brand new civilization. We’re the first Earthlings to surpass D&D’s renaissance-level technology, and we’ve only got a few centuries of high technology under our belts. We’re only a few thousand years removed from humanity’s first mastery of bronze and iron.

Your average D&D world is somewhere between our living and Vance’s dying Earth. It’s in a Renaissance-technology dark age, and it lives among the ruins of more magically and technologically advanced empires. Lots of them. Many campaigns have their own lore about human and humanoid empires, and lots of editions have hints of aeons where other creatures ruled the world – dragons, demons, giants, yuan-ti, aboleth, the Queen of Chaos, all in turn. Archaological sites are not rare. In fact, there’s an undisturbed dungeon, a relic of a past age, just outside the PCs’ starting town.

Your average D&D world has been around for a while. It’s possible that its best days are behind it. If you travel into its future for a few millenia, you’ll get to Dark Sun’s red-tinged wasteland. If you travel into the past? who knows, you might end up in d20 Modern, under a garish yellow sun.

Goblins: Interrogating goblins by torture seems to be creepily prevalent in D&D games. Anyway, it’s not necessary, because goblins will always tell you everything when threatened with torture, no Intimidate check necessary. They’ll mix in 20% malicious lies, but they’d do that under torture as well.

Hobgoblins: Hobs will inform you of their name, rank, and serial number, and then try to escape or commit suicide as soon as possible. They can withstand torture very well, but they will enthusiastically betray their superiors if you convince them that their efforts are unappreciated.

Bugbears: Bugbears are vicious, unfeeling brutes. By “unfeeling” I mean “they don’t have pain receptors.” However, they are easily bribed.

Orcs: If you try to torture orcs, or even tie them up, they will get so mad that the pulsing vein in their forehead will burst and they will die.

Gnolls: Stressed gnolls undergo frenzied visions of following Yeenoghu and ripping people limb from limb. In this state, they slaver foam, snap their teeth, and giggle curses. They don’t give information.

Elves: Elves enter a trance state much like the gnolls do, except theirs involve dancing in magical glades instead of running down panicked humans. Instead of slavering foam, they murmur, “More tea?” and “Sindural shall play the aulos while Mistral distributes the mystic crumb cakes.” But elves will tell you anything during pillow talk.

Half elves: Half elves never have secrets worth knowing.

Dwarves: Dwarves have high pain tolerance and unending reservoirs of stubbornness and hatred. However, they love beautiful things. Instead of torturing them physically, make them watch as you hit a dwarf-made ewer with a hammer.

Halflings: Torture is unnecessary to get information out of halflings. Just engage them in friendly small talk. They will accidentally reveal 1d4 secrets per hour, from closely-guarded pie recipes to secret tunnels into the castle.

Humans: Torture might work on humans, but you probably shouldn’t do it. Because torture is evil.

I’ve talked before about why 10th level spells exist in the game world’s past but not its present. Here are some appropriately overpowered 10th-level wizard spells.

Because every such spell is lost to history (most 10th-level spell users having destroyed their own civilizations), each spell must be researched based on tantalizing clues from forbidden books. An easy Wisdom check reveals that this is a bad idea.

10th-level spells are more the purview of villainous NPCs than PCs. I bet that they can be cast with lower-level spell slots, if cast in a suitably long and interruptable ritual.

10th-level spells:

Animate all dead. Area: the world.

Detect Great Old One’s Thoughts. Your brain explodes. Everyone within 1000 miles is subject to a Feeblemind spell.

Disaster. Range: 5 miles. Everything is destroyed and everyone is killed within a 1 mile radius. Caster’s choice of meteor strike, inferno, volcano, chasm, plague, tarrasque, etc. There may be unintended lingering side effects (deadly ash, tarrasque, plague, etc)

Erase person. Range: 400 feet. Kill one person and destroy their body and gear, no save. Everyone except for the caster instantly forgets the person ever existed. Their deeds are re-ascribed to others. People with close relationships to the erased person get a saving throw after 1 week of being confused by inconsistent memories.

Immortality. The spell all the liches are searching for. Warning: may attract liches.

Mordenkainen’s dimensional domain. Warps space so that an area of up to a 20-mile radius is moved into a pocket dimension, accessible only by rules set by the caster (only through a specific wardrobe, appears one day every 100 years, etc). Don’t bring a bag of holding into this domain.

Planar blink. Duration: one hour. Every turn, you may teleport anywhere you’ve scried or visited on any plane, or you can teleport to a random location on a plane you’ve heard of but never visited, or you can teleport to a random location on a random plane. Besides the classic planes, you can visit alternate timelines, other D&D campaigns and game systems, and the theoretical dimension where game-players control your actions, so you can kill the guy controlling you.

Power word: damn. The target dies and goes to hell. They get a saving throw after a year. Even if they return, they’ll be pretty traumatized.

Soul swap. Touch someone. You permanently swap bodies, no save. You each keep your game stats but trade appearance and age.

Trans-galactic jaunt. The caster and 10 friends can survive comfortably in space and fly at 1 light-year per hour. They can finally explore the vast seas between stars and discover that, however a big deal they might be on their planet, they’re level 1 in cosmic terms.

And finally, the real reason level-10 spell research is a bad idea:

Detect 10th level spell research. The one wizard in the multiverse who knows this spell also knows Planar blink and Erase person.