Mouldering in the Darkness

Everything rots. Everything gradually breaks down into uselessness. This is simply a law of nature. In the context of dungeoncrawling this is super-important, in that all that stuff you're after (precious metals, scrolls, clues to buried treasure hidden in ancient frescoes, etc.) is likely to have been down there a loooooooong time.

With that consideration I present the following (derived from an original in the Dragon Kings high-level play sourcebook for the only true Dark Sun setting):

Time Elapsed	Paper	Wood	Metal	Soft St.*	Hard Stone**
30 days	Faded
1 year	Fragile
2 years	Brittle	Faded	Paint
5 years	Crumbled	Fragile
10 years	Dust	Brittle	Etching		Paint
20 years		Crumbled		Paint
50 years			Relief
100 years		Dust		Etching
200 years			Form	Relief
500 years				Form
1,000 years					Etching
2,000 years
5,000 years					Relief
10,000 years
20,000 years					Form

* Limestone, sandstone, marble, tufa, etc.
** Granite, flint, mica schist, nephrite jade, gritstone, etc.

The table shows the average effects of time and the elements on various materials. This will vary be prevailing climate (hot, wet and windy will accelerate erosion, cold, dry and windless retard it). Items protected from the elements will take longer to erode. Multiply erosion time by ~10 if in a sheltered location, and by more if items have either been properly curated, or sealed in a preservative anaerobic environment).

Paper and wooden objects fade over time, making it difficult, but not impossible to read or identify surface features. Fragile objects must survive an item saving throw versus fall every time they are used; brittle items must survive versus a crushing blow. Crumbled items are unusable but still identifiable as papyrus or wood; dust is completely unidentifiable and unusable.

Metal and stone items wear away over time, their shapes smoothing out until the item is completely worn away. Paint indicates that artificial coloration is gone or unrecognisable; etching means carved letters or pictures are worn away; relief indicates that deeply carved letters or images are severely eroded; form indicates that time has eroded away all but the basic form of the original stone or metal.

Why am I bothering with this? Well, there's an ongoing subplot involving Hobgoblins (think a timelost version of Japanese holdout soldiers + some Tekumel flavouring) and a particular time-locked sub-level of the Vaults...

Related links:

• The Clock of the Long Now
• Life After People

Thoughts? Opinions? Requests for breakdown times of other materials?