[[quoteright:350:[[VideoGame/BloonsTowerDefense http://static.tvtropes.org/pmwiki/pub/images/img_0123_5.JPG]]]]

A video game sub-genre of strategy where you [[ProtectionMission defend a building from monsters]] using other buildings, sometimes with a unit or two to back you up. Similar to MultiMookMelee, Tower Defense games have you facing [[ZergRush wave upon wave]] of "creeps"[[note]]("Creeps" being the term used for random monsters in ''VideoGame/WarcraftIII''; as a lot of Tower Defense maps were made for [=WC3=], the name stuck.)[[/note]] until a given number reach their goal, or you survive the final wave.

Creeps will move along the path that is either:
* Static: Creeps move along the same paths.
* Dynamic: The placement of towers will determine the paths which creeps move along. Dynamic paths usually create a strategy called "mazing", allowing the player to make long, winding paths that force the enemy to take the longest possible route to their destination, all the while being blasted by the towers herding them.

A typical Tower Defense game will have:
* Creeps that behave differently. Some are {{Fragile Speedster}}s or {{Mighty Glacier}}s, some are {{Asteroids Monster}}s, others [[AirborneMook can fly]] over towers and [[DungeonBypass bypass most of your defenses]], etc.
* "Boss" creeps on certain waves.
* A strategy that requires a balance of producing more towers and upgrading existing ones. More important in dynamic path type ones.
* Balance between different towers. Ideally, none of the tower types should be completely useless.
* Commonly, a "survival" mode in which each level retains the towers you built in the previous level and/or the enemies get tougher as the game progresses instead of simply increasing in number.

As of lately, a trend in this genre has started to develop where the games will feature the ability for the player to be the attacking force pitted against the towers. Some games in the genre get to the point of devoting themselves entirely to this, eschewing the defense element altogether. It is also the basis of the MultiplayerOnlineBattleArena, with ''VideoGame/DefenseOfTheAncients'' being basically born as a 5 vs 5 reverse tower defense using ''VideoGame/Warcraft3''[='=]s hero mechanics.

Another form of Tower Defense features a single tower or gate on one side of the screen, which is then beset by the Creeps marching forth to destroy it. The player is usually given one or more weapons directly controlled by them, while upgrades may add automatic defenses and defenders.

The third form of defense game is the "Tug-of-War"/BeamOWar style. In which there are two towers or bases at each end of one or more paths, and the player(s) and AI send different units down the path to attack the enemy base(s). Opposing units that meet will fight each other, and the object is to push the enemy force back to their own side and destroy their base(s).
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!Examples of Tower Defense as a Full Game:
[[index]]
* ''VideoGame/AegisOfEarthProtonovusAssault''
* ''VideoGame/AgeOfEmpiresCastleSiege''
* ''VideoGame/{{Antbuster}}''
* ''VideoGame/AttackOfTheMutantPenguins''
* ''VideoGame/TheBattleCats''
* ''VideoGame/BloonsTowerDefense''
** ''VideoGame/BloonsMonkeyCity''
* ''VideoGame/BubbleTanks'': [[http://www.kongregate.com/games/HeroInteractive/bubble-tanks-tower-defense Tower Defense 1]], [[http://armorgames.com/play/6338/bubble-tanks-TD-1-5 1.5]] and [[http://armorgames.com/play/13734/bubble-tanks-tower-defense-2 2]]
* ''Castle Doombad''
* ''Castle Panic'': A ''[[TabletopGames board game]]'' tower defense game. Can be played solo or co-op.
* ''VideoGame/CityConquest''
* ''Comet Crash''
* ''Create-Your-Own Tower Defense''
* ''[[http://armorgames.com/play/12044/crush-the-castle-td Crush The Castle Tower Defense]]''
* ''VideoGame/CursedTreasure''
* ''VideoGame/DefendersQuest'' (with features of a traditional RPG)
* ''VideoGame/DefendersQuestII''
* ''VideoGame/DefenseGridTheAwakening''
* ''VideoGame/DefenseWitches''.
* ''VideoGame/DesertMoon''
* ''VideoGame/DesktopTowerDefense''
* ''VideoGame/DillonsRollingWestern'' (which also mixes in Action elements)
* ''VideoGame/DungeonDefenders''
* ''VideoGame/DungeonOfTheEndless'' (combined with {{Roguelike}})
* ''Evil Defenders''
* ''Fantastica''
* ''Fieldrunners''
* ''VideoGame/FinalFantasyCrystalChroniclesMyLifeAsADarklord''
* ''[[VideoGame/CrystalDefenders Final Fantasy Crystal Defenders]]''
* ''Flash Element Tower Defense''
* Website/FunOrb's ''[[http://www.funorb.com/info.ws?game=orbdefence Orb Defence]]''
* ''[[VideoGame/GemCraft [=GemCraft=]]]''
** ''[[http://armorgames.com/play/3527/gemcraft-chapter-0 Gemcraft: Episode Zero]]''
** ''[[http://armorgames.com/play/10317/gemcraft-labyrinth Gemcraft Labyrinth]]''
** ''[[http://armorgames.com/play/15760/gemcraft-chasing-shadows [=GemCraft=] 2: Chasing Shadows]]''
* ''VideoGame/GhostHacker'' and its sequel
* ''{{VideoGame/Glissaria}}''
* ''VideoGame/GrimGrimoire''
* ''VideoGame/HeroicArmiesMarching''
* ''VideoGame/ImmortalDefense''
* ''VideoGame/IronBrigade'' (formerly known as ''Trenched'')
* ''[[http://www.kongregate.com/games/nerdook/kill-the-heroes Kill The Heroes]]''
* ''{{VideoGame/KingdomRush}}''
* ''LocksQuest''
* ''VideoGame/MetalSlugDefense''
* ''VideoGame/MiniRobotWars'' (known as Tiny Defense on the iOS system)
* ''VideoGame/MondayNightCombat''
* ''[[http://www.kongregate.com/games/fortunacus/mushroom-revolution Mushroom Revolution]]''
* ''VideoGame/NinjaTown''
* ''VideoGame/{{Onslaught2}}''
* ''VideoGame/OrcsMustDie''
** ''Orcs Must Die 2''
** ''VideoGame/OrcsMustDieUnchained''
* ''VideoGame/OsomatsuSanHesokuriWarsBattleOfTheNEETs''
* ''[[VideoGame/PatchCon PatchCon! Defend the Library!]]'' is a VideoGame/{{Touhou}} fan game that has elements of Tower Defense games except characters can move. It also has an actual tower defense mode that plays it straight.
* ''VideoGame/{{PixelJunk Monsters}}''
* ''VideoGame/PlantsVsZombies''
** ''VideoGame/PlantsVsZombies2ItsAboutTime''
* ''VideoGame/PokemonTowerDefense''
* ''Prime World: Defenders''
* ''VideoGame/ProtectMeKnight''
* ''VideoGame/{{Rampart}}''
* ''VideoGame/RatchetAndClankFullFrontalAssault''
* ''VideoGame/RevengeOfTheTitans''
* ''VideoGame/{{Sanctum}}'' (With a hybrid of first-person shooter)
* ''VideoGame/SavageMoon''
* ''Sol Survivor''
* ''VideoGame/{{Soulcaster}}''
[[/index]]
* ''WesternAnimation/SouthPark'' [[{{Engrish}} ''Let's Go Tower Defense Play!'']]
[[index]]
* ''VideoGame/SpaceRun''
* ''VideoGame/StarFoxGuard''
* ''Stickman Tower Defense''
* ''VideoGame/SystemProtocolOne''
* ''VideoGame/TowerMadness''
* ''VideoGame/ToySoldiers''
* ''VideoGame/ToysVsNightmares''
* ''VideoGame/WarDragons''
* ''Unstoppable Gorg''
* ''[[http://www.candystand.com/play/vector-td Vector Tower Defense]]''
* ''VideoGame/WhatDidIDoToDeserveThisMyLord''
* ''Whiteboard Tower Defense''
* ''Xeno Tactic''
[[/index]]

!Examples of Tower Defense as a MiniGame:
* ''VideoGame/AgeOfEmpiresII: Age Of Kings'' (and the expansion pack ''Conquerors'') had a "Wonder Race" game type, in which you are required to build a wonder and defend it for 200 years before your opponent(s).
* ''VideoGame/AnimalJam'' has "Pest Control", in which the player uses biological pest control[[note]]Venus fly-trap, frog, lizard, snake[[/note]] to prevent the pests[[note]]Ant, fly, cricket, dragonfly, beetle, spider, rat[[/note]] from reaching the end of the static path.
* ''VideoGame/{{Civilization}} IV'' came with a "Civ Defense" mod, in which one starts with a certain number of cities, spends money (rather than the usual "hammers") to add to their fortifications and defenses, and then horde after horde of barbarians come at you.
* ''VideoGame/ClubPenguin'' had "System Defender", in which the player has to set up cannons to stop the MechaMook from destroying the EPF Mainframe computer. Interestingly, while threats could be simulated by all players, there would be live threats that could be handled by members only.
* ''VideoGame/FinalFantasyVI'' and ''VideoGame/FinalFantasyVII'' are probably the {{Ur Example}}s:
** ''VideoGame/FinalFantasyVI'' has has an event similar to this halfway through the first part of the game; there's a difference in that you battle the mooks using the standard battle system, but otherwise the execution is the same.
** The Fort Condor mini-game in ''VideoGame/FinalFantasyVII'' is essentially a tower defense game.
* The TropeMaker was the various user-made defense maps in ''VideoGame/StarCraft'' - Sunken D, Turret D, [[GoodBadBugs Stacked]] Photon D, etc. The Starcraft editor did not allow you to create new units or buildings, so they usually made much more use of mobile units than most current Tower Defenses. See, for example, [[http://www.youtube.com/watch?v=mpgj_1dGlEw this video]] of Weed D, which is recognizably a fixed-path Tower Defense game except that [[UnbuiltTrope the "towers" being "built" are Mutalisks]].
* The TropeCodifier was Tower Defense maps for ''VideoGame/WarcraftIII''. The editor was much more sophisticated than Starcraft's, allowing for greater variety in attack buildings. Multiple subgenres appeared and proliferated, such as the Wintermaul clones.
** The expansion pack, Frozen Throne, contains a Tower Defense map as a bonus level.
* Some user-created maps for other RealTimeStrategy games follow this style.
* The ''IronGrip'' series is part TowerDefense and part {{FPS}}.
* A variation of this appears in Legion's Loyalty Mission in ''VideoGame/MassEffect2'', where Mooks must march towards you in a fixed path while you have Legion hack a few turrets around the area to shoot at them. Alternatively, you can just cap them yourself.
* ''VideoGame/ThreeDDotGameHeroes'' has a Tower Defense mini-game called Block Defense.
* ''VideoGame/AssassinsCreedRevelations'' had Den Defenses, where Templar soldiers assault one of dens controlled by the Assassins. Ezio is responsible for organizing the defense by placing barricades in the streets and various types of Assassins on the rooftops firing down upon them.
* Mann Versus Machine mode in ''VideoGame/TeamFortress2'' is something of a FirstPersonShooter version of a Tower Defense minigame. There is/was also a fan-made Tower Defense minigame mod in development.
* "Red's Mighty Feathers" from ''VideoGame/AngryBirds'' adapts the Angry Birds formula for the Tower Defense genre. The pigs are advancing upon the egg using their vehicles, and the Red Bird must protect the egg by popping the pigs with his new homing power.
* "Englos Defense", a bonus level in ''[[VideoGame/DeadlyRoomsOfDeath DROD]]: The Second Sky''.
* "Frontier Defense" from ''VideoGame/Titanfall'', added in Title Update 8.
* ''VideoGame/SunsetOverdrive'' has seven mandatory "Night Defense" missions where the player fiends off two waves of OD from attacking multiple Vats.
* ''VideoGame/{{Terraria}} Otherworld'' has segments like this, where the player needs to place down towers to defend against monsters attacking the purifying machines.
* ''VideoGame/PhantasyStarOnline2'' has two variants of this.
** The first is Mining Base, Emergency Quests where players are tasked with protecting towers against increasingly powerful and aggressive waves of Darkers while collecting crystals to unlock new weapons and defensive measures.
** The second is Buster Quests, introduced in Episode 5. The first half of these quests entail protecting towers from an onslaught of enemies, albeit with a wider array of weapons and defensive measures available from the start. The players are also tasked with raiding an enemy castle and destroying the boss therein.

!Examples of Tower Defense games that include the ability to play as the attackers:
* ''VideoGame/AnomalyWarzoneEarth'' - Considered by many to be the {{Genre Launch}}er for Tower ''[[InvertedTrope Offense]]'' games. Here, you upgrade a constantly moving force to [[AllYourBaseAreBelongToUs attack an enemy base/garrison]] filled with turrets.
* ''VideoGame/{{Villainous}}'' - Also a Tower ''Offense'' game where you play as the villain on his quest to take over the lands.
* ''VideoGame/ArmoredCore V'' - A MechaGame where most of the online component consists of you assaulting other team's territories akin to a glorified 3D-Tower Defense game. As with everything else however, being intercepted by that territory's owner and prepare for a Team Deathmatch style game instead, with all the turrets present. Like real Turret Defense games, turrets run the gamut from "squishy little targets" to "hard as a barnacle to remove", and combinations of turrets often give even the most experienced players trouble.
* A game literally named ''Anti-Tower Defense''. You select versions of certain robot creeps to casually walk (argh) through a progressively harder tower network.
* ''VideoGame/PlantsVsZombies'' on the Xbox 360 has the [[CompetitiveMultiplayer 2-player versus mode]]. The zombies' side has you attacking the plants and attempting to get into the house, while defending your targets from the plants' attacks. All the versions of the game have a simpler version of this in the "I, Zombie" minigame, where you have to pick zombies to attack a pre-selected set of plants.
* Tower defense makes up half of the gameplay in ''VideoGame/LeagueOfLegends''. Towers can dish incredible amounts of damage against heroes, but they will always target creeps first; the goal is to use teamwork, strategy and your minions to take out three enemy towers on each lane, then an Inhibitor that prevents you from spawning super creeps or "winions", then two final towers and finally the enemy's Nexus. Because the other team has the same goal, you play simultaneously as attacker and defender.
* ''VideoGame/{{Stronghold}}'', a series of castle-building games which are mostly defensive except for the rare mission where you play an invading army trying to get into an opponent's castle. These also involve setting up a complex supply chain, managing taxes and morale, but for the most part, the aim is to build a big wall around your keep, and stock it with as many archers and crossbowmen as possible to pick off the approaching invaders.
* ''VideoGame/DungeonDefenders'' has an event match called 'assault' where, "in an unexpected twist, YOU have to attack THEIR crystal!"
* ''VideoGame/PokemonTowerDefense'' also features sections where your 'Mons go on the attack.
* ''[[http://www.doggnation.com/ Doggnation]]'' was originally designed as a Tower Defense game, but this eventually changed into more of a puzzle game where you have to help the "Doggs" carry specific blocks to upgrade their castle.
* ''VideoGame/DeadSpaceIgnition'' has a HackingMiniGame that is a tower Offense game. You send out an unlimited number of computer viruses to break down the computer firewalls and get to the computer program before time runs out.
* GameMod ''VideoGame/RedAlert3Paradox'' is unique in that it has BOTH sides of a tower defense game as RTS factions.
* ''Defenders of Ardania'', a Tower Defense game set in the ''VideoGame/{{Majesty}}'' universe, has you do defense with towers and offense with units at the same time.
* ''VideoGame/TheMightyQuestForEpicLoot'', at least if you're on the defense.
* In ''VideoGame/CityConquest'', both players have a city, and each player switches between offense and defense.
* ''VideoGame/GhostHacker 2'' has segments where you place Mooks to collect Data cubes from a security system. In the first game, it was a bonus level. Unlike many examples, your mooks can instantly destroy the enemy towers should they run into them or their "nodes".
* ''VideoGame/DragonWars'', when you aren't defending your own base from being attacked. The other point is to attack other players' bases with your dragons.
* ''Royal Revolt'' and its sequel are similar. Most of the time, you're using your PlayerCharacter king/queen to attack other players' castles.
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