Details to spice up your ruins
1. Graffiti: Graffiti is a great way to make a ruin feel alive. Its presence tells the PC’s that they are not the first to encounter or explore this location, and that they need to be wary of whatever recent visitors have left behind. Logic says that there will be more graffiti near population centers and less if any in remote areas. Lots of graffiti in a desolate area should signal to PC’s that someone has taken pains to visit this location. What made it worth the trip? Graffiti is denser near the ruin’s entrance and dwindles as the PC’s explore. A particularly spectacular or evocative room deep in the ruins might be the sight of a pilgrimage, filled with tags, murals, symbols and messages.
Casual or degenerate cults may use graffiti to document their presence, usually through poorly-drawn symbols or iconography. Graffiti can also entice delvers to go deeper, promising spectacular views or loot. It can also attempt to ward away the foolhardy, warning explorers of lurking danger.
2. Standing, stagnant, water is always a problem. It can range from ankle deep to chest high, even completely drowning sections of the ruin. Water can obscure the floor and hide hazards such as pitfalls, jagged debris and predators or scavengers. Stagnant water is also a vector for disease. Populate your ruin with blind, diseased aquatic predators mutated from vermin, biotech or former residents.
3. Former (or current) residents or visitors have left vehicles for safe passage through the ruins. These might be small boats, a cache of security passes, hazmat or hard suits, or any other items that will provide safe passage through the fungual dark. The vehicle might have a map, compass or GPS on board. It might be moored next to a bit of string leading into the darkness.
4. Ruins are often piled with accumulated litter. It can be from the original occupants, from later occupants, or the ruin can have been used as a dumping site. Garbage can be difficult terrain, an obstacle to be overcome (rubble to be cleared; debris to be burned; biomass to be…shooed), a poisonous or diseased hazard, a nasty (or helpful) creature’s lair, and/or a source of hidden loot.
5. Ruined or obsolete technology either found in the ruins or pictured in the ruin’s archive gives clues to past history or function of the ruin. Such ancient tech might provide a source of loot or a discovery by opening a passage, revealing a view, or opening communication with another site. Dead tech may be the McGuffin of an adventure. Perhaps the PC’s have seen (or will see) an image or plan of the tech in its pristine state, but it is now rusty, dusty and possibly re-purposed.
6. Giant virtual or actual maps of locales as they appeared at previous time are always fun. some information is valuable; some is dangerous because of how things have changed since the maps were made. Large maps can reveal the locations and original functions of other ruins, especially ones with a related or complementary function.
7. Air becomes thinner, stinky, and stale…or unexpectedly clean and fresh. Air can be a toxic or insidious hazard, or simply provide ambiance.
8. The ruin has an unexpected secondary or hidden functionality: medical, military, educational, re-educational, research, disinformation, surveillance, counter-espionage
9. Darkness kills peripheral vision; bright lights kill night vision. Explorers can use red light to mitigate night-blindness; this could trigger beneficial or dangerous effects. Darkness hides hazards; darkness plus water is especially difficult and dangerous. Think Death Star trash compactor at ¾ light, and you’ve got it.
10. Decay, both of the physical building and the institutions that gave it meaning. Rust, burnt-out, broken or malfunctioning light fixtures; faded, discolored or peeling paint; dust--nano and mundane; broken or malfunctioning holo-projectors or screens; long-dead security measures; doors marked "restricted access" left open; emptied closets or other evidence of looting or flight. If these are absent, this indicates some agency (nano-scrubbers, maintenance automatons, a cargo cult) is keeping the ruin fresh either to continue its suitability for a defunct purpose or preparing it for a new one.