The Mutated Nesting Roachswarm I mentioned in one of my latest blog posts could infest more RPG´s than just the Mutant Future(tm). After all, the movie I took it from was not even fantastic, was it? Let´s see where those buggers could turn up as well…
I used to play Cyberpunk 2020 when I was young, and while I have not being playing it for years, I still have found memories of it (mostly because I was young and it was itty-gritt-grimdark compared to Shadowrun). This game is -not- ripe with mutation, and there was only one instance of genetically breed beasts I remember of (in an official module, that is), but I guess that an infestation of mutated cockroaches cannot hurt here. I would see them as a “natural” mutation there, a side effect of environmental pollution and toxins. I guess those buggers would be kept in check by the city as they DEMAND immediate and harsh action (e.g. guys in protective suits and loads of gas), but if the PC are the first one to stumble into a growing infestation, things could turn out bad for them quickly. An “intrusion” missions could take them to (and through) a place that is home to such an infestation
Rules/Cyberpunk 2020: It would take between 6 and 12 points of damage to disperse a swarm, but only area effect weapons will do any (meaningful) damage to it. Likewise, the swarm itself would not have any penalties from being wounded, as individual bugs getting squished or roasted won´t effect the mass as a hole one tiny bit. They are quick, so their Movement Allowance is 7. They do not attack like regular combatants would in melee. Instead, if they are closing in on a target (and they NEVER need to make any rolls for running, nor does they get a penalty for it or for terrain) they will always swarm it unless it is successful on a defensive action (i.e. “block”) against a difficulty of 20. If they are not fend off, they will begin to bite. Each round, the victim must pass BODY test. The test starts with a Difficulty of 10, and the difficulty increased by +5 for every further round the victim is swarmed. If the test is failed, the victim is paralyzed and will be killed and infested within a minute unless somebody comes to the rescue.
FATE offers as many game worlds as the GM and the players can imagine, so their might be a niche for an infestation. A swarm would be a “faceless NPC”, but a real danger if not avoid or faced with the right equipment at hand.
Aspects: a wave of creepy crawlers, hard to stop,
Skills: Physique (+3); Notice (+2)
Swarm Attack (Stunt/Physique): The Roachswarm uses Physique instead of fight, and will get a cumulative +2 bonus on its attack, starting with the second round.
The Swarm (Stun/Physique): Only attacks that affect a larger part of the swarm all at once my harm the swarm.
Last but not least, I still have the Alpha Playtest Kit of Chthonian Highways around. In that game system this Roachswarm would be able to Charge even if there are obstacles in the way and be able to attack unless the victim succeeds on a Difficult Parry roll. There will be no damage, the victim must succeed on a Body roll instead: the difficulty starts with 10 for the first attack, but increases by +5 for every successive round that the victim is bitten by the swarm. If the test is failed, the victim will be paralyzed for 2d6+5 minutes. If nobody is there to defend or rescue the victim, this means death and infestation. The swarm itself may only be harmed by attacks with an area effect [Vitality: 4; Defense: 8; Push Limit: 0]
Being charged by the swarm calls for a  Sanity Check to prevent 1d4 points of stress
Being swarmed by the roaches calls for a  Sanity Check to prevent 1d10 points of stress.