This article is a detailed discussion of the game mechanics surrounding the use of non-targeted warp interdiction fields (“bubbles”). Brief summaries of other mechanics involved will be given, but additional articles will cover these other concepts in detail.
When you give a command that will result in your ship entering warp state, the server will effectively draw a straight line (the warp vector) from your current location. Somewhere on that line, is where you want to land (the gate, station, bookmark, etc.). At this point, the server will also create a grid containing your exit point. If, on that grid, there is a bubble intersecting the warp vector, you will land there instead of your intended target. Note, that because this calculation is done at the time you enter warp/pre-warp state, you can very well land on a grid with bubble and not be caught in them; these bubbles went up after the calculation was complete and therefore you won't be caught. Additionally, the origin grid does not have the same restriction; you can warp through a bubble when departing, so long as you enter warp state outside it.
Primarily used to prevent outgoing warps, these bubbles are often found in groups around the station undock and in-line with celestials about the station. An abundance of bubbles around a station or POS is known as “bubblewrapping” or “[redacted for ungentlemanly language]caging” the object.
Catch bubbles are those placed to shorten a warp, leaving the full radius of the bubble between the ship and its intended target. If the quarry tries to fly to the original intended destination, they will be subject to interdiction while they do so. If they turn around, their alignment time will be increased as they must fully halt forward velocity in order to do so.
Drag bubbles are the opposite of catch bubbles; their leading edge is placed past the intended target, lengthening the warp and “dragging” the quarry past their destination. In general, this provides a single vector for escape (backwards).
Hunters can jettison/anchor canisters and drones on the “landing zones” of their bubbles in an effort to decloak ships that land there. This is effective at catching any CovOps vessel that might otherwise effectively escape the trap (as hitting a bubble does not automatically decloak you).
There are several classes of ships in the game that are immune to bubbles (non-targeted interdiction). Specifically fit T3 cruisers, some interceptors, and the Victorieux Luxury Yacht all share this ability. If you are flying one of these ships, you have already done everything possible to avoid bubbles.
Bookmarks placed directly up or down from a gate (as long as they are over 150km from the gate) are useful for avoiding drag and catch bubbles. An off-grid bookmark close to the gate is a near guarantee of bubble avoidance (unless your bookmarks have been somehow compromised). Such a location would allow you to d-scan the gate for bubbles.
You can occasionally use other celestials as “poor man's pings” that change the angle at which you approach a gate. This will sometimes save you from drag/catch bubbles, but diligent hunters will often set up traps at each celestial vector.