Random encounter A random encounter is a common RPG situation . It most often occurs when the player character is traversing a distance across the world map or a dungeon , resulting in a conflict with a randomly chosen opponent . In " Fallout " and " Fallout 2 " , random encounters are only encountered on the world map and can be as simple as a trader wishing to show you their wares , or as convoluted as finding a tin man who needs to be oiled . Not every encounter is hostile . Not every dangerous encounter involves aggressively minded NPCs ( such as " Stampede " or " Dehydration " encounters in " Fallout " ) . Not every encounter even has an NPC on its map ( " Old battle " encounter ) . Some random encounters are unique , and happen only once during the course of the game ( or not at all ) - these are commonly known as special encounter s . The kind of encounter depends on many factors . The main one is player ' s location on the World map . Others may be the player character ' s Outdoorsman skill , Karma level or reputation , as well as their previous actions during the game . " Fallout " . Encounters on Desert squares depend on the player ' s location on the world map ( split into 13 areas based on towns and other landmarks ) . Encounters on Coast , Mountain and City squares have less categories to choose from . All terrain types primarily use the player ' s Luck to determine encounter type , as well as if the player is a Childkiller or passes Outdoorsman checks . ( the skill checks only applies to certain encounters ) Several encounters do not appear in the un - modified game . These are usually " bad " encounters such as large groups of Super Mutants . It is not clear if this was intentional or an oversight . " Fallout 2 " . The random encounters in " Fallout 2 " are determined by the player ' s location on the worldmap , his level and global variables governing it and finally , the chances of encountering one , stored in WORLDMAP . TXT . They can be anything : a number of molerats foraging , a press gang or a traveling merchant caravan . " Fallout 3 " . Random encounters in " Fallout 3 " can happen in certain pre - defined places in the Capital Wasteland . They usually consist of unique situations , enemy encounters or small tasks for the player . A random element is the place where a given event will appear . Once a special encounter has been activated in a particular area no other random event will occur in this area . You can save outside the spawning area and keep reloading if you don ' t get the encounter you want . In principle , there are two different types of special encounters in the game : unique encounters and repeatable ones . Unique encounters will only occur once per playthrough whereas repeatable ones can occur multiple times . Another difference is that repeatable events can happen in any of the random encounter locations but unique encounters do not ; there are 2 sets of unique events , each of which occurs only in a certain set of locations . " Fallout 4 " . While traveling through the many landmarks of The Commonwealth , the Sole Survivor can experience some random encounters . " Fallout Shelter " . Dwellers sent to explore the wasteland may find locations to explore . At this time an icon appears in the upper - left corner of the screen . Tapping it allows the player to order the dweller to explore or ignore the location . Exploring it opens a side - exploration area where the player directly commands the dweller , and an objective in exploring the area is given .