The addition of “irrelevant” details adds local colour to a campaign world, giving the impression that the DM has thought very deeply about the history of even the smallest architectural feature.

Following a discussion we had on the site, I thought we could start up a thread to post the pre- and post-apocalyptic effects of a comet/minor planetary impact on a campaign world.

The Despotic Queen of Shiant has decreed that a competition will take place in the month of Oconerry. She will have built a labyrinth through which the contenders must pass in order to win the ultimate prize: her hand in marriage.

The characters are stranded on an island, where a wizard, corrupted by the powers of the first Blue Book, has been killed by his own magical experiments. They will discover the awful truth that lurks in his subterranean workshop, and a seed of evil will be sown...

The grisly anthropomorphisation of a rockfall...

The Great Gate of Calast is not like other gates. It's got a mind of its own...

In the darkness in the south transept of the Cathedral of Isielles stands the resplendent Clock of Shadows. It tells more than just the time of day...

To give a world a feeling of otherworldliness, it is best to replace some standard, everyday objects by imaginitive replacements. I thought I'd turn to musical instruments as music often defines (or embodies) a culture.

This is just a first idea, feel free to post some more, because I will...

The silver necklaces whose inset gems display the status of the wearer.

Creepy, Crawley, Buzzing, Digging, Biting, Building, Sticking, Jumping, Clicking, and all the other things these small things do.

This looks like an elaborately fashioned wooden egg-cup, but it is a powerful magical tool, used mainly by witches to conjure up spirits and familiars.

Carmo keeps a shop in the backstreets of Erezi. It's not often visited, Carmo makes people feel...uneasy. Even the veterans of the Erezi underworld are uncomfortable being alone with Carmo. But they need to buy their traps from somewhere...

Two sly-looking men turn up in town accompanied by a third man who says very little and who they don't allow to be seen much.

An icky sideline plot to a forest adventure.

She has everything: stunningly good looks, sharp brains and oodles of power: she's going to be a Queen. The only drawback is that she doesn't want to be a Queen.

A (fairly sketchy) outline of a one-off adventure I ran based around the (time-honoured/hackneyed) Tunguska Event of 1908. As such it is quite specific (hopefully not hackneyed) and will probably best serve as a specimen for dissection to get those parts you can use in your own adventures. But then this is an Ideas Guild after all...

A mysterious quarry. Feel free to suggest explanations - it's just an eerie thought that struck me that I intend to play with.

I don't know if I posted about it before, but I have always wanted to run an adventure set in a library. The following is a sketch of an unusual premise and a possible plot-hook.

Dragons, being huge and meaty, are the ideal habitat for countless unpleasant parasites.

A disembodied hand enthralled by an evil wizard to fetch books for him.