"It's not a question of if you're paranoid. It's are you paranoid ENOUGH."
Welcome to the world of running Cyberpunk. Everyone is out to frag the characters, you have their girlfriend's parents hire a hit-team to take them out, and their apartments are in the Combat Zone. They pack big heat just to go to the corner store to pick up a Slovenko Lovely, and they sit half-naked in the dry-cleaner's lounge waiting for the weekly de-smelling of their body armor to be complete. One of these days the friends, corporations and gangs of their enemies are going to find them and perpetrate a serious revenge trip, and they know it.
Living on the edge is lonely, and stressful. Now add some cyberware and interesting drugs to the equation, and you have yourself some paranoid characters. If you have characters whose humanity is particularly low (especially if they are high on the Paranoia scale), or are really stressed out, or on drugs that enhance paranoia, just remember that ANY event can be cause for paranoia! The players might not always role-play it, but you can certainly make suggestions.
Here are some ideas for random encounters (or ARE they random?) with some possible explanations (not including of course, "It's all in your head"). We personally prefer the "coincidence" explanations, but sometimes it's fun to make a plot of it. Some can develop into sub-plots, others are just fun to introduce once in awhile for flavour. Enjoy.
Also, pretty much at random, let the players make an awareness check (especially when they are alone). If they roll a 20 or 25 (your choice) or better, they notice something "strange" (since this is a "strange" world). Little things like missing cutlery (oops, left it on the couch), lack of cockroaches (the neighbours roach traps finally started working), people watching you (yer a freakin' edgerunner man!), the prime parking spot in front of your building is available (lucky sod), the flyers and junk mail at the entrance has been cleared away or neatly organized, someone insists on opening the door for you, guy at the corner store pays for your coffee or paper...
PS: In our games, it seems as though whenever there is about to be a gunfight, the GM makes us declare where we are in a room, and draws out a map. Or when we're walking down a sewer in the dark, he makes sure he has our marching order. To keep players (and hence the characters) on edge, keep producing maps of every location, and ALWAYS insist on a marching order. And never underestimate the power of music: old Einsturzende Neubauten and Skinny Puppy is noisy and unpredictable, and great to keep nerves raw.
A character's drink tastes funny: someone is trying to poison them, someone just slipped them a drug (hallucinogens or aphrodesiacs are popular) as a malicious action, or as a joke, the pop has gone flat, the diet version was substituted, waiter delivered a poisoned or drugged drink to the wrong character or table, waiter got the order wrong ("Oh- you wanted a SCREWdriver, not the PILEdriver- sorry, ma'am!"). Variants include the character's drug tastes funny if ingested, drug leaves a bizarre aftertaste, drug has other effects (some beneficial, some not): is it a plot against the characters? Or against the street?
Characters hear voices from the stairwell. They smell smoke: a black-ops team has been hired to off the characters by one of their enemies and is smoking cigarettes, a black-ops team has been hired to off the characters by one of their enemies and is setting up a distraction, a black-ops team has been hired to off the characters by one of their enemies and is trying to lure the characters out of their apartment, someone is keeping an eye on the characters (see "Tail" for more ideas), a grey-ops (or black-ops) team has a job elsewhere in the building and is just passing by smoking their cigarettes, there is a serious fire elsewhere in the building, there is a small fire (trash burning, kid's prank, etc) elsewhere in the building, the building has a strict no-smoking policy and tenants smoke in the stairwells.
At a restaurant, the characters see a beefcake in a suit wandering around, trying to discreetly check out the patrons: he is a scout for a hit about to happen on the players, he is a scout for a hit about to happen on someone else, he is a talent scout looking for the players, he is a talent scout looking for someone else, he is a bodyguard for a local corp/gang-boss/celebrity a few tables down, he is the manager of the restaurant who forgot to put on his pin and is checking that the staff are doing their jobs. He is just some beefcake looking to join his friends for dinner.
The power goes out at the characters' aparment/coffin: a hit is about to happen on the characters, a hit is about to happen on someone else, someone plugged in their volt gun and used the microwave at the same time and burnt a fuse, the building has lost power for scheduled maintenance, the block has lost power, the city has lost power, someone forgot to pay their hydro bill.
Out of the blue, a complete stranger wants to be your friend: They follow you around, they ask questions to your friends about you, they get chummy with your family, they offer to do you favours, they do favours without you asking. This in itsself could be creepy enough, but they might have ulteriour motives, and their idea of a favour might make you uncomfortable. ("I thought that guy you were meeting in the park was going to kill you, so I sniped him. My bad, sorry!") Heck, sometimes the character won't even know that their new friend exists- just weird things will happen around them: their bill at a restaurant will be paid, drinks will be sent to their table, their windows will be washed, their dishes done, enemies threatened or killed...
Blackout v 2.0
The characters can't remember what happened the night before: they were drugged, they drugged themselves and don't remember it (maybe the character hasn't realised yet that his Blue Glass or Enduro500 have side effects, or for whatever reason his favourite drug and alcohol produce memory loss- see Drug Rules and Drug Production), maybe they're insane and have multiple personalities controlling their actions and they don't know it (see Project : Gestalt), they sustained a head injury, they're absent-minded, or nothing memorable happened. Or maybe they have been brain-burned against doing something they almost did last night, or finally their Command Kill was activated and their corporate "sponsor" had them do something distasteful. Or maybe your memories have been downloaded into a clone, and you are that clone?
A piece of equipment, cyberware, software gets quirky: Maybe it just moved or acted in an unpredictable way, or better than it's supposed to, or outright stopped working. To the paranoid character, it could mean a conspiracy, obsolescence, or... DIRT.
Character notices the same person/car wherever they go: Gee, a white Honda MetroCar? How uncommon is THAT? Or perhaps there's a new poseur-gang in town that the player hasn't heard of yet. Could be a coincidence, perhaps someone really IS following them: could be a long-lost friend or enemy, could be someone who thinks the character is a long-lost friend or enemy, could be one of the friends of an enemy. Maybe it's the cops checking them out for a suspected moving violation, or a minor infraction like littering, or the character fits more or less the description of a wanted person in the area, or the cops are honestly out to get the character- they might want him as a snitch, or for a minor indiscretion, or for some horrendous crime.
The rain in Spain stays mainly on the plains
A stranger approaches the character and passes them a note, or says an address, or a cryptic message: It's an honest mistake: the stranger just passed along important information meant for someone else, or is giving a code word and is expecting a specific code response, or is expecting to be given the briefcase (or bag, or envelope) the character is carrying. Of course, it could also be a vital clue to whatever plot the characters are trying to unravel, or the address for the secret rave tonight/this weekend. Or it could be just some crazy, or a guy who gets off on this sort of thing and likes messing with peoples' heads. Variants include phone calls or misdirected email or mail.
Do you smell something?
Character or characters smell something unusual: The character's facial piercings have collected some nasty smegma or something. Your nasal filters are due for their annual cleaning. Pet or NPC farted. One of the cars in traffic is using methane and has a leak. There is a gas leak nearby, or in your home. Rancid kibble under the sofa. Dead NPC in the closet. HitMan nearby just farted. Party member's neo-appendix (or other gastro-intestinal augmentation) is processing some NASTY smells. Someone is using almond air freshener (smells like cyanide).
Things that go bump in the night
"Did you hear that?": A loud "thud" from above - it's not a break-in, your neighbour is moving his furniture. It's not a hit team wrecking the place next door, it's a kid that jumps off sofas. Breaking Glass - oops, dropped the mirror. Footsteps down the hall to your door and stop (AAA Booze Service dropping off their card). Very quiet scratching noises at your door - a friend is writing a note for you, using your door as a surface to write against. Backfiring automobiles, local gunfights, or your neighbour watching Kung Fu cinema?