Acid Rain

[Arkay_The_Arcane]

A small event with heavy consequences.
Acid rain could come in three variants, lightly corrosive, medium corrosive and highly corrosive, depending on the concentration of acid. It could come with a message like

"A chemical fire nearby has released acid solutions in the air, which are now raining down on your colony!"

Lightly corrosive acid rain will do slight damage to crops outside, and cause a mood penalty to anyone outside due to the acid irritating their skin. It will also slightly damage their clothes.

Medium corrosive rain will, over an extended period of time, do damage to skin, do more damage to plants & clothes, and can turn shallow water into "acidic water" which will cause a skin irritation mood penalty. The acidic water will eventually turn normal.

Highly corrosive acid will very quickly kill plants, burn skin the moment it touches it, burn holes in clothes, and has a small chance to burn through regular roofs, as well as damaging weaker types of walls (wood & limestone).

People hit by medium and high corrosive rain will get burns on non-protected parts of their bodies (So keep your nudists inside). Most realistically, but not necessarily, a new type of wound could be added, an acid burn.

[Skryabin]

Oh, my friend, isn't there enough sorrows in this Rimworld? 

I am glad no one suggests an event like a nuclear bomb exploded nearby (with 10% chance of falling right on your colony)... 

[Bolgfred]

This sounds very similar to toxic fallout(which could be a synonyme for acid rain).
But if I get you right, you want a fast progression, short duration event that will require fast reactions but doen't cause long-term problems, right?

Actually acid rain could reducde fertility for a period of time. Could be an overlay like snow, which get slowly washed away by water or by time reducing fertility by 100% on max, making only fertile soil able to grow crops in the worst case.

[Wanderer_joins]

Whereas the event itself is very similar to toxic fallout, i think there could be different intensities in toxic fallout and volcanic winters: mild/ harsh. A harsh toxic fallout would be more toxic and maybe result in toxic burns and toxic pounds, a harsh volcanic winter would be more extreme and create a quasi permanent darkness, blocking solar panels and preventing crops from growing.

[TwistedSoul]

I think this is a great idea, even some of the bodies in our Solar System exhibit weather like this such as Venus, Io and Titan.
Our planet also has acid rain, less extreme but it's still acidic none the less.
Why shouldn't it occur in some remote system?

[dogui]

Nice idea.
+1