Fallout 4 random encounters

Static encounters
Also called scene markers, these are triggered on cell load.

Travel encounters
Travel encounters can be the most difficult to happen upon: They are triggered when the player enters the cell where the trigger is located and spawns characters that travel between these markers. Typically, they travel along roads, rather than overland.

General encounters
You can find these encounters almost anywhere in the Commonwealth.

Campsite encounters
Campsite encounters are triggered on cell load, and take place at, well, campsites.

Assault encounters
Assault encounters are triggered when the player enters the cell, placing buildings with defensive markers plus distant markers for attackers to spawn at.

Treasure Hunt encounters
These follow a similar pattern! you encounter a dead person with a note on their corpse. If you read the note, you’re pointed in the direction of a (random) location, and a map marker appears to reveal where a steamer trunk is located.

Chokepoint encounters

 * Notes: Chokepoint encounters are loaded when the player enters the cell and, like the name suggests, are encountered in areas that are chokepoints.