Player-Run-Plots (PrPs) are an important part of the way String Theory as a wider story works. Anything from rallies, to bank robberies, to once-off group scenarios through to more extensive, multi-scene plotlines constitute as PrPs if, ultimately, they are GMed by a player for other players.
There are things we ask players do before embarking on running these kinds of scenes. First, ask yourself: how big a scale is this scene? What might it turn into, even if it starts small? Such things to consider might be the amount of NPCs involved (cops, bystanders, etc.) as well as the amount of PCs, what factions might be involved, and if this would gain media attention and make some kind of wider impact.
If by these measurements, you think your scene/s will have a broad scope of any kind, we ask that you talk to staff. Whether this be via a +request or even a quick page to "sanity check" your idea, it's important that we know what's going on! Because we control factions such as Homeland Security as well as keep an eye on wider media/social reaction, it's both good to know ahead of time as well as be able to offer our input.
When it comes to NPCs, GMs have the ability to control and dictate the surrounding, environmental factors which includes non-player characters. Common sense is the key when it comes to this aspect of PrPs, and what is and isn't okay to assume, and what will and won't help along your scene. The only blanket restriction we can offer is that Homeland Security NPCs are typically off-limits without some form of clearance via staff, and to be wise/double-checking when it comes to police and other official-like NPCs.
Remember that deaths matter, too, even NPC deaths! Such things will generally get media attention, so keep that in mind when it comes to particularly violent scenes. On that note, remember also that GMs have the responsibility of ensuring that IC actions lead to appropriate IC consequences.
For information on long-term NPCs to further plots, please consult the newsfile on NPCs, and as ever, let us know if you have any questions.