Dronejam



""BOB-jam? Apply grenades liberally!""

- Bungie, Marathon.

When annoying NPCs stand in front of a door or passage and won't move.

This is usually accidental, and was far more common back in the days of tile-based maps, when a door would be one space wide and could be completely blocked if a mindless NPC happened to wander in front of it. Still occasionally shows up in modern games, if the Player Character can get "caught" on the character models of NPCs. Best case scenario when this happens is the NPC moves after a few seconds and you can move on as before, only slightly more annoyed with life. Worst case scenario; you may have to reset.

Either way, you have to wonder -- why can't you just push these people out of the way? Note that several 16-bit examples allowed you to; for example, Breath Of Fire 2 and Secret of Mana had NPCs move out of the way if you walked into them for a moment.

If it's intentional, placed there by the designers, you've got one of the more obvious forms of the Broken Bridge. A favorite tactic of the City Guards. See also Insurmountable Waist-Height Fence.

Action Adventure Games

 * The Legend of Zelda Four Swords Adventures has the Village of the Blue Maiden. In front of the Seeker's HQ, there's a long line of obstructing NPCs. To actually manage to enter the HQ, you have to use the Pegasus Boots to crash into the wall and scatter the NPCs and go through the door before they manage to return in line. The game also has a woman obstructing another important house. To get in you actually have to manually push the woman to the side.
 * In The Legend of Zelda the Minish Cap, once you beat the first dungeon, you were unable to get past the guard blocking the west exit until you learnt the Spin Attack. He, and the guards blocking the north and east exits would run/walk parallel to you, preventing you from passing.
 * Also of note: the ridiculously fat King Zora who blocks the entrance to Zora's Fountain in The Legend of Zelda Ocarina of Time. Other characters in the game pull off the same living Broken Bridge stunt, but none with quite the elan of King Zora.
 * The "line of NPCs" trope gets its fair share of use too: both The Legend of Zelda Twilight Princess and The Legend of Zelda Skyward Sword have a strangely cohesive group of NPCs blocking access to a specific area (A long queue for water blocking South Hyrule Field in TP, and a bunch of women chatting after laundry was done blocking the residential area of Skyloft in SS).
 * Spectrobes averts this trope by having every last NPC being both intangible and immobile.
 * Assassin's Creed had Altair or Ezio lightly push NPC's from his path when walking through a crowd, or collide with them more forcefully if he was running.
 * The former being less effective against the beggar women and minstrels, who actively try and block your path.
 * Ezio can cause Drone Jams by throwing some money to the ground while fleeing. Any civilians in the vicinity will rush to pick them up, slowing down any enemies trying to catch him.
 * Alice: Madness Returns has a lot of obstructive characters in the London areas, forcing you to go through scripted areas.

Adventure Games

 * In the Hamtaro game, Ham-Hams Unite! for Game Boy Color, in one level, there's a hole you need to get through to get Cappy, but there's this one hamster who gets in the way and won't let you through, because he's "scared".

Driving Games

 * Destruction Derby 2 has this (semi-)intentionally on the Chalk Canyon track, featuring a very narrow passage directly after the start. If you nudge an opponent in this section this usually causes them to get stuck and completely block the road, causing a pile-up involving every single opponent that follows. They will still be there when you complete your first lap, though of course now you have to get past them in order to continue racing.
 * Opponents in Forza Motorsport 3 tend to drive in tandem to block you from passing. On tight turns or narrow tracks, this can result in a pile-up involving you.

Edutainment Games

 * Happens a lot in Slime Forest Adventure. It got so bad the developer put in a "whistle" item that speeds up the movement of nearby NPCs for a few seconds, so they'll get out of your way faster.

First-Person Shooters

 * In Marathon, your only hope was to shoot a nearby wall, which would "wake up" NPCs and hopefully cause them to get out of your way.
 * Assuming you are nice. The game actually encourages you to grenade your own allies at one point - it was even a requirement for the "Vidmaster Challenge" to kill every friendly you came across.
 * There was now-well-known secret text hidden on a map with a lot of Bobs (human friendly NPCs) on it: "Bob Jam? Apply Grenades Liberally".
 * More annoying in the levels where you have Pfhor as allies (the Pfhor being the normally-hostile aliens), as Pfhor Hunters are both larger than Bobs (and thus it's a lot easier for them to block doors and passageways) and a lot more dangerous if you tick them off (i.e. accidentally shoot one, which would quite reasonably cause it to become hostile to you). I've been killed trying to use the "shoot the wall and hope it moves" trick and accidentally shooting a Hunter, who then decided he'd mangle me.
 * Blake Stone: Aliens of Gold for the PC. A bit of setup for the uninitiated: In this FPS, there's a group of NPCs called informants who work against Dr. Goldfire by giving you ammo packs, food tokens for the vending machines (the better to heal bullet wounds with, my dear), and information. The trick is that they look exactly like the scientists who are loyal to Goldfire. Most of them move around, which isn't usually a problem. However, they do seem to have their own zones which they will not leave. One such zone boundary was a door at the far end of a one-person-wide hall with a one-way door at the other end. If the informant went in first, and you followed, the informant would be trapped between you, the invisible boundary, and the walls of the hall. The only way out of that one would be to shoot the informant, making him no longer an obstacle but depriving you of your floor bonus for leaving all the informants alive.
 * Half Life 2, with the co-dependent rebels that squad up with you. You can tell them to go away, but they come back after a while to crowd around you again and obstruct your movement.
 * Standing next to one and looking at them appears to be Gordon's way of saying "Move out of the way", as they'll back up and say "Sorry doc" when the player does this. But it doesn't work very well if two more are behind the first.
 * The game also does this intentionally at various points to make you listen to certain dialog or prevent you from going Off the Rails. A single NPC can block most doors reliably.
 * In the original Team Fortress and Team Fortress Classic, griefers could block narrow doorways or passageways with their body, or knock people off small platforms with explosives. This was changed in Team Fortress 2: now players on the same team pass through each other (but not through enemies) and are not budged by friendly fire. This has actually become a tactic for detecting spies, where players will try to run into people on their team, since they'll fail to go through a disguised spy.
 * Quite surprisingly for a game build on a modern FPS engine, Vampire the Masquerade: Bloodlines has this problem. Some NPCs seem to be inside magical rectangles that block all movement through them. This leads to some situations where an NPC will be standing in a gate/passage with visibly enough room to move around or over them only for the player to walk into a solid, invisible barrier as they try to walk past.
 * It's a problem in the Asp Hole especially.
 * Judge Dredd for Xbox has a variation on this problem. Several tasks require leading innocent people to safe zones. If you don't get them to follow -just- enough, they can stand just inches out of the zone and the next event is not triggered. By the way, some of the zones aren't as safe as they seem...
 * Counter-Strike can cause player fueled versions of this. Hilarity Ensues when a griefer enters a server.
 * In Left 4 Dead, Survivors can pass through each other, as can player-controlled Infected. In the developer's commentary, it's mentioned that this was done to prevent Griefers from being able to push players off of roofs, killing them. Played straight between Survivors and Infected, however - during random zombie hordes, it's typically impossible for players to continue on at all until they've killed everything. The sequel is a bit better about this, with both adrenaline that prevents zombie attacks from slowing you down, and melee weapons that cut through them faster than even the auto-shotguns.
 * The original Rainbow Six often forced you to shoot your own team-mates when they refused to move out of the way. Particularly egregious since the point of the game was suffering as few casualties as possible.
 * The same goes for Ghost Recon, your fellow teammates tend to block the door way you just entered, or stand on a narrow bridge your trying to pass, although you are free to switch to the other teammate if needed.
 * In Medal of Honor: Frontline, two guys block your path upstairs at the Golden Lion pub, and you must tip the piano player to play a song to distract them.
 * Rather annoyingly at the end of BioShock (series), when you end up escorting a little sister, she can block your way quite effectively, even in the middle of a firefight.

Hack and Slash

 * In Diablo II, the various undead minions summoned by Necromancers were decidedly solid. They were patched into being passable for the very reason this article exists.
 * The Maggot Lair is among the most hated areas of the game because in multiplayer you get stuck behind your party members.
 * Also seen in Diablo II the unpatched version: City gate. Sand leaper. Attacks disabled inside city limits. Hilarity Ensues.

MMORPGs
"Wildly-reproducing mice are usually a hindrance, but they may be used sometimes to your advantage: you can slow down a fast enemy by letting the mice reproduce out of control. Once they are everywhere the enemy will wait for the mouse in front of him to move before advancing on you; he won't think of harming the mouse to get at you. This leaves you with the ability to get past the enemy or around him/her by simply slashing through the mice (assuming you can slash your way through the mice faster than the enemy can pound the cr@p out of you as you pass him)"
 * This is one of the common complaints in NPC-heavy areas of the MMORPG City of Heroes: not only are player characters unable to push NPCs out of the way, NPCs are perfectly capable of pushing player characters around. This is not as bad as it could be, since NPCs are generally constantly in motion. The henchman-centric Mastermind class compounds the problem, although they can command the henchmen to move out of the way using the "Go To" command.
 * However, Controller/Dominator pets cannot be given commands at all and a trio of Fire Imps can still clog a narrow doorway. At least some pets like Singularity and Dark Servant are intangible, making this problem irrelevant as you can walk through them.
 * World of Warcraft was specifically made with no character collision to avert this. So instead of a few dozen players standing in front of a set of doors preventing others from entering or exiting, you get a few dozen players standing in the middle of an NPC others might want to click on/interact with. Yay.
 * Nowadays, even World of Warcraft has NPCs with collision, though it's handled by building an invisible force field around them or placing them on a pillar. This was made because huge characters (Tauren!) on even huger mounts (Netherdrakes!) loved to sit down on highly frequented NPCs. In addition to rendering these NPCs very hard (if not impossible) to click on, players often intentionally flagged themselves for PvP combat, causing opposing faction players attempting to activate the NPC to attack the flagged player instead. This would then invoke the wrath of the guards, who proceeded to kill the "offending" player. Much nerd raging ensued.
 * You can turn on NPC lifebars and click on that instead, but most people don't know that. It's still pretty annoying to do, but at least you can work around the problem instead of waiting for them to go away.
 * There is an area in Guild Wars, near the broken wall, with a narrow path. You can't see to the end so if you like to explore (as I do), you will walk down it and your hirelings will follow behind..Not too bad since you can walk through hirelings, but I was a Ranger-type...And your pet is solid! I was trapped on a narrow ledge, no way back, and my pet would not move. I had to teleport back to town and it was a good distance away.
 * Averted in Star Trek Online: Most NPCs are effectively insubstantial (or their collision-detection boundaries are incredibly small); you can essentially run right through anyone in your way.
 * Crossfire RPG allows to push characters standing on the way (which also allows to move encumbered characters faster). But there is some jamming - as Survival Guide explains:

Real-Time Strategy

 * In general, this is a great tactic to use to protect your more fragile units: use larger, tougher units to block off enemies while your ranged units and SquishyWizards go at it.
 * Odd example: in Blizzard's RTS title StarCraft, some units are known for bad pathing (stupid movement AI). Some genius decided to take advantage of this to intentionally jam up a ramp (or other small passage), thus pushing the opponent's units out of the way. You then go tell the workers to do something else, and rush up the ramp. The unit used? It's called a drone. The maneuver is called a dronedrill. It's now a fairly common tactic. To get to the point, when it fails (not uncommon), your worker drones just sit there getting butchered by enemy units while your fighting forces mill around behind the dronejam. Especially annoying since these aren't even NPCs - you technically are telling them where to go, which means you screwed up.
 * Supreme Commander has some serious routefinding issues, among them workers who stand in the way of the unit they are assisting. It makes it look like the ACU plays soccer when pushing kicking an Aeon tier 1 engineer out of the way, but slows things down a lot.
 * In Sacrifice this becomes a real problem for larger armies, especially for melee-using flying units who need a lot of room to manoeuvre and do uninterrupted attack runs. Dragons, in particular, become almost useless in groups larger than two.

Role-Playing Games
""What do you want from me, crab?!""
 * All the Final Fantasy games prior to the move to 3-D. In most of them, unless the NPC is blocking an area you're not supposed to get to, pressing against them for a few seconds will make them hurry out of the way for you.
 * Pretty much summed up in this link
 * Of note is Final Fantasy IX, in which you move through NPCs if you press up against them long enough. The same is done in Final Fantasy XI, and you can also move through PCs like this as well, but the "pushing though" must be done for each character model you're trying to get though, which can cause a bit of a delay in a crowded area.
 * At least one since the move to 3-D- in Final Fantasy VII it's possible to get stuck in small shops behind fellow customers- they try to move out of your way, but there's not enough space.
 * In the GBA remake of Final Fantasy I, one of the levels in one of the bonus dungeon involves NPCs basically trying their best to block you from moving around in narrow corridors, forcing you to either walk on "spiked tiles" where a random encounter is guaranteed, or just pulling your hair out trying to get that TINY opening to get past when there aren't even any spiked tiles to bypass them.
 * Final Fantasy Mystic Quest got around this by letting you leap over them.
 * The SaGa games for the Game Boy (aka the Final Fantasy Legend series). Partially ameliorating the problem, a player can jump over an interposed NPC if there is a free space on the other side and the NPC is not an intentional obstacle.
 * The Golden Sun games avert this. Your overworld character will actually stick out his hands and push NPCs aside in any direction you make him.
 * Pokémon. As a bit of a compromise, pressing against an NPC will cause them to hustle out of the way. Usually.
 * The notable exception being the cranky Old Man in Viridian City, who won't let you pass until his coffee takes away the grumpiness. (In the original he's just drunk and needs to wait until he's sober.)
 * When Saffron City is under siege, several buildings are blocked by Team Rocket members standing in front of the door. Bizarrely, you can only get past one when he falls asleep and somehow moved one square to the right.
 * In the fourth generation games, there's a man that blocks access to Sunyshore City because...there's a blackout. Exactly why that would make it dangerous to go to the city is a mystery.
 * And then there's someone who escorts you to see Brock's Gym. Several times. As in, until you actually beat him, the bastard will not let you onto the next route.
 * Another particularly annoying one: in Platinum you're chasing a criminal who just SET OFF A BOMB. He leaves the vision of the player, but if you follow the path which you saw him leave from, you come to the entrance of a lakefront blocked by two generic men with cameras saying "we're filming the lake." Guess where the whole evil organization sets off another bomb...
 * However, it's implied in companion materials that the two are disguised members of Team Galactic.
 * A very obnoxious one in Black and White involves a policeman standing at the entrance to a post-game route who refuses to let you past. His reason for not doing so? "There's something up ahead and you can't go through here." Nothing in the entire Pokemon canon hints as to what this mysterious "something" is.
 * In Tales of Phantasia, there's a crab in the Alvanista port that is there specifically to block your access to a chest (at least in the PSX version). Talking to it cause Cless to lash out at it.

"Guard: We're renovating the tower! Jay: That's nice. Could you move? The shortcut's over there. Guard: We're renovating the tower! Jay: ...stupid NPC. And later, if you decide to take the staircase at the other end of the shortcut up... Guard: We're renovating the tower! Jay: Are you STILL here?!"
 * In Star Ocean: Till the End of Time there is a particular NPC in Airyglyph who just seemed to not get the point that you need to get through that door, dammit!
 * A huge issue in Mount & Blade, wherein the player can easily get stuck behind the lines of their own army, as there is no way to force the NPCs to move. It gets really ridiculous during castle sieges...What's this, you have an army of three hundred? Congratulations! You outnumber the enemy two to one! Have fun attacking the enemy four at a time, because there's only one ladder!
 * On narrow walls, there are times when the two armies are so tightly packed that soldiers in the middle of the group literally cannot move a step, and are forced to watch the ensuing battle, unable to take part until every rank in front of them is cut down.
 * Live a Live features a sort of puzzle in the Prehistoric Chapter. You come into a room with one caveman. You talk to the caveman, and another one shows up. Now both are running around frantically. Talk to one of them and a third one will run in. Keep this up and eventually the room will be overrun with cavemen running around, making it quite hard to navigate. This is not a large room, by the way. Finally, your goal is to talk to the twentieth cavemen (this despite the fact that all of them are identical). If you get it right, you'll get a reward and all but one of the cavemen will leave. Get it wrong and they'll just leave, making you start over. Try to leave the room in the middle and you'll find it all but impossible.
 * Knights of the Old Republic provides a way to deal with this: the player can take control of a party member and move them out of the way. But it's still annoying. In the sequel, party movement has been fixed so they automatically make way for the currently controlled character.
 * Jade Empire mostly fixes this problem for large crowds: Not only do the random extras move out of your way, you can also walk right through them if they don't move quickly enough.
 * Mega Man Star Force suffers this trope badly.
 * Occasionally a serious problem in Fallout. Avoided in Fallout 2 by a special "Talk to the hand"-looking button used to move friendly NPCs out of your way, even during combat. (When used on cattle, it causes them to tip over, of course.)
 * Most notoriously in the series, was the Gun Runner island in Fallout. Their building was on a small island surrounded by toxic waste with a one tile wide plank for a bridge. If a companion followed you on to the bridge, you better hope you have an older save because there is literally no way to get out.
 * In Fallout 3, you get to hire several different companions based on Karma, Money etc; One such companion, Fawkes, who can be hired towards the end of the game, takes up almost an entire doorway in-game. If you're stuck in a tight space with Fawkes stuck in the doorway, he is practically unmovable, and although it is possible after several minutes of running into him to free your character, many people choose to re-load their save instead.
 * Or you know tell him to go home and wait an hour.
 * The Citadel is another likely place to get trapped—Brotherhood scribes love to gather in hallways and bonk repeatedly into each other, issuing a greeting with every collision.
 * Pleasantly enough, the Companion Wheel in New Vegas brought back the Fallout 2 workaround.
 * This was a big problem in some of the older BioWare games using the Infinity Engine, especially in closed spaces like narrow hallways and, of course, doors, which made it impossible to do anything constructive if a single character was getting overrun by a group of smaller enemies. Baldur's Gate II corrected this problem by allowing player characters to automatically "bump" NPCs and other party members to the side for a moment while they passed.
 * Neverwinter Nights and its sequel have this issue, made all the more annoying by the fact that the D&D rules explicitly state you can pass through ally-inhabited spaces. Possibly worse is the fact that, in the earlier Neverwinter, passing "friendly" NPCs can nudge you out of their way, possibly into a piece of level geometry. You don't know frustration until one of your own summoned animals shoves you through a pillar, trapping you forever.
 * In Nethack's Sokoban sublevel, you often end up with a non-hostile creature standing between you and the pit you need to fill. Unicorns are especially a pain, as no one can teleport in Sokoban, and this causes them to just stagger endlessly back and forth. However, since these aren't true NPCs, there are ways to "deal" with them - damaging ray spells work well.
 * A sidequest in Lost Odyssey is almost entirely based on this. In the Kelolon worshiping sidequest, the only difficulty whatsoever is found in various NPCs that will randomly but deliberately block off paths for an arbitrary amount of time. They'll move eventually, but often not before you run out of time.
 * The actual design flaw also shows up on occasion, including a particularly annoying case: after stealing the speedboat, you can get cornered on deck by one of your party members, forcing you to reset and steal the boat all over again.
 * Sword of Vermillion actually lampshades this. In one of the later towns, the tavern owner is serving free food to celebrate your arrival, causing his place to be overrun with many NPCs. If you do make it to the other end of the room, one NPC will tell you "This place is so crowded, you might have trouble getting out!". Indeed, you most likely will have.
 * Task Maker: Pushing against an NPC will cause your character to say "excuse me," and after enough tries, "get out of the way!" However, it won't necessarily get the NPC to move.
 * Affectionate Parody RPG Maker game Jay's Journey has a guard that is rigged to only walk back and forth through a narrow corridor (which is a shortcut out of the area that was accessible earlier in the game). When Jay speaks to this guard, he tells the guard to move... but is only met with a single useless phrase over and over again.


 * Averted in Might and Magic 6-8. Friendly NPCs can block your way but there's a special command (Yell) that will make them move out of the way. This does create an interesting situation in the 7th game, when you get to the City in the Sky and have to shout "MOVE!" at angels...
 * EarthBound has a maze made of NPCs. You have to shift them aside by talking to them.
 * An NPC in The Elder Scrolls IV: Oblivion will try unsuccessfully for a few minutes to nudge someone out of the way, then whip out their sword and callously murder the obstacle. "Radiant AI" apparently means "Don't fuck with me."
 * In Morrowind, if there was a drone jamming your doorway, you were out of luck. The community made a mod out of necessity that forces the pathfinding algorithm to roam.
 * There was a console command to fix this: just enter the command RA (Reset Actors) to put everyone back where they belong. You might need a hotkey macro assigned to that command.
 * In Daggerfall you could walk through enemies if you weren't careful. If you were trying to drop down a hole and there was an enemy in the chamber below you that was aware of your presence, however, more than not it would stand right under where you would fall. And then you'd be stuck on top of it until you find the magic angle from which you could hit it.
 * Similarly, Deus Ex's NPCs will frustratedly pace back and forth against obstacles you've put in their path. If suitably barricaded so that they can't make progress, they'll eventually get fed up and smash through the obstruction---without attacking. They just nonchalantly stroll through as it explodes into fragments at the touch of their shins.
 * The same happens in Gothic. But at least the NPCs warn each other or you to get out of the way before they start getting rough on you.
 * Happens in Paper Mario: The Thousand-Year Door: An irate Zess T. will block a door to the west side of Rogueport because you stepped on her contact lens. You can order a replacement lens immediately after the incident, but if you forget to, you won't be able to purchase one until chapter 3, leaving her blocking your way for some time.
 * If you've played Persona 3, you've probably gotten ambushed by Shadows at least once because you were running from it and ran smack into one of your party members. When not trying to flee, it's less of a problem because your party will run around you to get back behind you if you head their direction. It's also averted for NPC characters, as they all have fixed positions.
 * This problem was fixed in Persona 4, which has your party members stay so far behind you that they won't get in your way if you run towards them.
 * The Code Geass RPG for Nintendo DS has a few instances of guards blocking item boxes (including the one containing the Guren Mk-II Kai parts). Talking to them goes into a Geass sequence: ordering them to sleep or dance permanently blocks the item, while ordering them to commit suicide or go home clears the way.
 * In Fable II when you reach a certain level of celebrity annoyingly adoring townspeople will crowd around you and often get in the way.
 * They'll sometimes follow you into buildings, crowding the exit and making it difficult or impossible to get out. At this point, your only options are to climb to the top floor and hope there's a window to jump out of, or to scare them away by unsheathing your weapon.
 * Chrono Trigger features a pretty literal example. Geno Dome, in the far future, contains a one-eyed guard bot that won't let you through to claim a key. There's no slipping past until you find a deactivated unit of the same model, give it a jump, and lead it back to short-circuit the guard and lock them both into a permanent staring contest. So, really, jamming the drone is the solution.
 * Another example occurs early in the game right after Crono's jailbreak, when the guards chase the party into Guardia Forest and cut off the exit. What makes this example particularly egregious is that you were flattening guards left and right not two minutes ago.
 * Albert Odyssey: Legend of Eldean includes a dronejam of the game-resetting variety. When visiting dragon-man Gryzz's hometown, inspecting every possible item receptacle like RPGs have taught us to do can randomly lead to one of the NPCs blocking your only path out of a certain corner and getting stuck themselves. Naturally, walking into NPCs in this game doesn't make them move. Fortunately, there's nothing in that corner to find, so you can avoid the bug without missing anything.
 * Avernum still has the tile-based variant, as of Avernum 6 released last year. There are few Dronejams by design, many more occur from NPC roaming.
 * There is a particular X-rated freeware game where, at one point, the player can get trapped by a mouse.
 * Final Fantasy Adventure brutally averts this trope in that the player can kill NPCs, providing a rather vicious solution to the problem.

Simulation Games

 * Animal Crossing allows you to push townsfolk around by walking or running into them—especially useful if they've randomly fallen asleep outside. However, they'll get mad at you if you shove them too much.
 * The best part is in the Nintendo DS version of Animal Crossing: Wild World, the "normal" personality will get upset and may even say a line about how you could have just asked them to move if you wanted them to move, making this something of a Lampshade.
 * In the game SimAnt, often when trying to enter/exit an anthill, your travel click will instead be interpreted as "bug the hell out of the ant that was just clicked."
 * Inverted in Magicians Quest Mysterious Times: While NPCs will usually move out of the way if you try to walk into them, if you stand in their way while they're walking, they'll get mad at you for blocking them.
 * Most every critter in the tile-based Dwarf Fortress takes up one whole tile when they stand in it. However, any number of creatures can lie down in the same tile. To pass in narrow corridors, one dwarf/kitten/dragon/whatever lays down and lets the other crawl over it. Optimizing fortress layouts to avoid the resulting traffic jams caused by people having to lay down and stand up over and over again was at one point a fairly important part of fortress efficiency.
 * Critters (and their remains) will also prevent doors from closing, resulting in serious hilarious security breaches during sieges. One memorable incident from Boatmurdered involved a monarch butterfly jamming the gate during an elephant attack.
 * The Sims had this problem when two or more Sims would attempt to leave through the same door, resulting in horribly annoying traffic jams. The problem was fixed in subsequent Sims games, and now the Sims can filter easily in and out of doors, even if there are multiple Sims using it at once.
 * NPC freight ships are the bane of entrepreneur-type players in X3, because they have an annoying tendency to clog up docking ports on player-owned stations (particularly ones that produce Inexplicably Popular Goods like computer parts). It's so annoying that somebody wrote a script to force them to undock.
 * Almost averted in Spore. All NPCs can be easily pushed out of the way. . . with the exception of your crew-members in the Galactic Adventures expansion who never walk unless they're following you, which provides a bit of a Dronejam catch-22 if you find yourself wedged between a crew-member and a wall (or between two or more crew-members). They won't move unless you move, and you can't move unless they move. You can sometimes get out of this with a high enough jump ability, but quite often they end up blocking you from doing that as well.

Sports Games

 * This can be a serious problem in Football videogames, if your running backs get stuck on your own players or your AI receivers run smack into the referee.
 * Watch a 'Football Follies' video. This can be Truth in Television.
 * In Mutant League Football, if you run into the referee you're as likely to plow straight through him. Ludicrous Gibs ensue.

Stealth-Based Games

 * In Assassin's Creed you can gently push NPCs out of your way. A controller button is dedicated to this exact purpose. (Of course the other way of getting through a crowd is running against it, in which case you will push NPCs violently to the side, but that will draw a lot more attention.)
 * You can also tackle bystanders out of the way while running. Though it can be tricky to pull off successfully when you're bravely fleeing from a horde of city guards. Some bystanders can and will knock you on your ass.

Tabletop Games

 * Used in-'verse in Dungeons & Dragons. Living flesh blocks any ethereal travel. So, all the walls of high-security buildings either have gorgon blood mixed into the mortar or are sort of alive and thus impenetrable for self-styled ghosts, but what to do with its door? Simplest solution is a big sentry blocking the doorway.
 * The Yu-Gi-Oh card game has a card called The Dark Door, which prohibits your opponent from attacking with more than one monster per turn. Essentially, this forces their monsters to Dronejam each other.

Third-Person Shooter

 * The Crusader series of games sometimes gave you or the civilian in question bad timing; just as he entered a doorway, the civvie would raise his hands, surrender...and then refuse to move. Simple enough to remedy: kill the idiot who won't move out of the way of the big armored guy with a gun.

Wide-Open Sandbox

 * Prototype has an animation if you run into an NPC of Alex Mercer violently shoving them out of his way. He'll be more gentle if you have a side-menu open. Alternatively, you can jack a tank or use the armour power and watch the corpses fly.
 * Civilian ships the X-Universe games are infamous for hogging docking ports at player stations. They'll buzz around randomly in a sector for a while, then dock at the nearest station for about ten minutes - this includes your stations, when there is only one docking port left. They can prevent player ships from docking at the station temporarily, and the only way to stop this from happening (without mods or scripts) is to prevent any non-player ship from docking, which can limit your profit potential.

Turn-Based Strategy

 * Dronejamming is a good tactic for this genre in general. Even if you can't stop an enemy unit completely, you can still force them to take a less direct route to get to your more vulnerable units. Whether they waste a turn or just go for a unit that can take a hit, it's a good thing you blocked the way.
 * Even nastier if there's reaction fire or attack of opportunity, AI doesn't see "crushing anyone in the way" as a valid route and mission targets or taunting units has overriding priority. Attackers may run the gauntlet without retaliation while trying to get there via the only unblocked, but heavily guarded way.
 * In Civilization 2, this could get extremely annoying because this game had the concept of zone of control, which made it impossible for all but a few special units to move adjacent to squares surrounding an enemy unit, meaning that a rival civ could jam large portions of land with cheap mooks controlling not just their own square but all squares surrounding them, and you cannot get past them without sparking a war or negotiating a right-of-passage agreement. Naturally, you cannot utilize this rule because it only applies to the player; computer-control civs can ignore zone-of-control all they want without consequence. Thankfully, zone-of-control was not a concept which remained in the series past this game.
 * In the X-COM series, when fighting aliens in a Terror Zone (or later-game equivalents), NPC civilians would occasionally block a doorway or stairwell, preventing the passage of your soldiers. Fortunately, this being X-Com, you have several options aside from just waiting for them to move. You can shoot them (and lose points), stun them (avoiding loss of points, AND ensuring that they won't get a Face Full of Alien Wingwong and end up converted to Chyrssalids), Mind Control them out of the way (which turns them hostile towards you afterwards, since for mind control purpose there are effectively two "sides" toggled - they can't harm you, but your soldiers will reaction-fire at them), or shoot a hole in a nearby wall and walk around them. On upper floors, there's even the hilarious option of shooting the floor out from under them, causing them to harmlessly fall to the floor below.
 * In a bit of a reversal, the drawbridge during a siege in Heroes of Might and Magic III would stay open one of your people is standing on one specific tile, and if they die there, their body will hold the gate wide open for your opponent!
 * Gates in Age of Empires II were similar. At least you could lock them shut if you needed them to stay that way.
 * The first Shining Force has an interesting bug in the first town where two guards who actively block your path can themselves be blocked by a fellow townsperson, letting you leave town earlier than intended, without the rest of your starting party.
 * The Shining series is covered with this trope blocking doors and leading the party down paths where events are taking place.
 * Jagged Alliance 2 had a command that let you swap tiles with adjacent NPCs, specifically to avert this trope. Some exceptions do exist, as there are NPCs that will simply refuse to move if you try swapping tiles with them (which the game will kindly tell you).
 * Actually a legitimate strategy in Final Fantasy Tactics. Less so in the sequels, though.
 * In Advance Wars this is how you guard your indirect units.
 * A huge problem in the Combat Mission series, if you make the mistake that telling a large number of units to go in the same direction. Even if they start off in a well spaced and orderly line, they will inevitably dogpile around a choke point, and they will resort to taking ridiculously long routes around the blockage (instead of simply waiting a moment).
 * Advanced Strategic Command has a partial variation: allows units to bypass each other depending on circumstances, and certainly if they are on different height - so no catching airplanes with tanks or vice versa (or rather, not with reasonable number of them). But since an unit isn't allowed to stop on any hex with another unit even on a different height, it can be forced to either hold back or get too close - which denies advantage of longer-range weapons. For example: if suitable places 2 hexes away are blocked by hovercrafts or planes, a submarine will have to pass into the hex under reaction fire from depth charges (range 1) of a cruiser instead of shooting torpedo (range 2) at it with impunity as usual (popping up to shoot the blocking unit is a bad idea, as it invites reaction fire from the cruiser's cannon and possibly blocking unit, then retaliation fire for shooting at range 1, then it's enemy's turn...). So with a little forethought unreachable units squatting on the optimal approach help layered reaction fire to wipe out several attackers before they get to shoot - normally multiple units can get away with modest damage after drawing fire of longest-range weapons to allow passage for other units, but not when everything shoots them at once.

Tabletop Games

 * Common in many older Avalon Hill games, especially the tactical games such as Panzer Leader and Panzer Blitz where it was often a good strategy to use a weak unit, or even empty horse-drawn carts, to block entire columns of tanks on road in the woods.

Web Games

 * Habbo Hotel has suffered serious amounts of drone jam as a result of regular raids by hacktivist groups.
 * POOL'S CLOSED. DUE TO AIDS, DESU DESU DESU DESU DESU.
 * This can happen in Mitadake High, though with other players rather than NPCs. Luckily, since these are living players they'll generally walk around you, and if they go AFK you can just push them out of the way. It doesn't stop the occasional traffic jam as players swarm around to see something that's happened.

Non-Game Examples

 * In one Dilbert strip, Dilbert has an unfortunate encounter with a pair of oblivious slow-walking women.
 * In the virtual reality internet world of Snow Crash, Hiro has to enter an ultra-exclusive nightclub, where the entrance is so crowded by wannabes and hanger-ons that he couldn't have gotten anywhere close if it were real life. But since the software that runs the Metaverse has better things to do than map out millions of avatar collisions, he simply walks through the crowd like a ghost until he gets to the front.
 * Nerf Now suggests Anti-Air tactics, making fun of Advance Wars.
 * This often happens to Gronkh, and he usually snarkily comments it.
 * Awkward Zombie‎ presents: "The secret art of sitting down on a staircase so foes can't get past you and immediately give up trying", in Fire Emblem: the Sacred Stones.

Real Life

 * Ever try to walk down a narrow corridor, see someone coming in the other direction, and then end up getting into each other's way while trying to sidestep them?
 * Or get stuck in a hallway behind a pair of people walking as slowly as they possibly can?
 * Or, similarly, you're trying to pass through an aisle in a store, but can't.
 * Rural neighborhoods are likely to have one single-lane driveway-like road leading to several houses. Whenever you're returning or leaving home in your car, watch for neighbors happening to do the opposite at the same time.