->''"Slowly. Gently. This is how a life is taken."''
-->-- '''The Ancestor''', ''Videogame/DarkestDungeon''

Damage Over Time is a common VideoGame mechanic where, instead of sustaining one-time sums of damage from one attack at a time, a unit receives a negative status that inflicts a small amount of damage at regular intervals, independent of any other factors or further attacks against them. The definition of an 'interval' varies by game: In action-based genres these intervals may be measured in real time, while turn-based genres (including non-video games, like a TabletopRPG) may measure intervals based on "turns" or "rounds".

Depending on how long the effect lasts, the accumulated damage can become significant, especially if combined with an AreaOfEffect to harm multiple targets simultaneously. On a mechanical level, this is the opposite of GradualRegeneration (and the "Regenerate" StatusBuff), and some varieties may officially neutralize or counteract each other.

Note that characters who [[GradualGrinder prefer defeating opponents via this method]] are [[BadPowersBadPeople almost always evil]] due to the connotations of [[ToThePain slow, painful deaths]] (as opposed to the more-heroic quick and clean kills).

Damage over time can manifest from a wide variety of in-game sources:
* Any number of StandardStatusEffects -- "Poison" status is the obvious candidate here, but other status labels like "burn" or "bleeding" may cause it as well. A character who [[WizardNeedsFoodBadly needs food badly]] may also lose HP over time from starvation.
* A nearby hostile FieldPowerEffect
* Falling into any HazardousWater
* Falling into VideogameLava (or in some cases, just being in the same room as it, partially averting ConvectionSchmonvection)
* Characters who are AllergicToEvil ([[GoodHurtsEvil or vice versa]])

''(For sake of expediency, only list examples that are ''not'' covered by existing sub-tropes.)''

[[AC:Tabletop games]]
* From ''Tabletopgame/DungeonsAndDragons''
** Module T1-4 ''The Temple of Elemental Evil''. A {{PC}} in one of the four Nodes of Elemental Evil took 1-4 HitPoints of environmental damage per turn.
** According to the ''Manual of the Planes'' (1987), the same thing happened on some of the Inner Planes.
*** Characters in the Elemental Plane of Earth took 1-2 HitPoints of damage per turn (from the pressure of the surrounding rock).
*** {{PC}}s on the Paraelemental Plane of Ice took 1-6 HitPoints of cold damage per round.
** Fourth edition also features "Ongoing Damage", which is calculated at the start of each turn.
* In ''TabletopGame/{{Earthdawn}}'', the nethermancer spell "Pain" inflicts minor damage to the target each round it's in effect.
* The Sixth Edition ''TabletopGame/HeroSystem'' has a "Damage Over Time" advantage that can be added to most powers and attacks.
* ''Tabletopgame/MagicTheGathering'' has several cards that deal damage during a player's "Upkeep" step, in contrast to most cards which can only deal damage once at a time.

* ''VideoGame/{{Angband}}'' has "poisoned" and "cut" status effects that do this, with heavier wounds doing more damage per turn. Damage over time is also one of the effects of starvation.
* In ''VideoGame/{{Borderlands}}'', many weapons that deal elemental damage have a chance of causing damage over time as an added effect. Incendiary and corrosive [=DoT=] is relatively mild but lasts for a long time, while shock [=DoT=] wears off more quickly, but is much harsher.
* In ''VideoGame/{{Civilization}} 2'', helicopters received minor damage for every turn they spent in midair -- this was intended to simulate their limited fuel reserves without requiring them to return to base every time. Later ''Civ'' games removed this.
* In the first ''VideoGame/DarkCloud'', if a character's "Thirst" meter runs dry during a crawl, their HP begins to drain. (In the sequel, Thirst was merely a StandardStatusEffect that blocked healing.)
* In ''Videogame/EarthBound'', whenever a character receives damage or healing, their LifeMeter rolls down or up to the new value over time (rather than instantly), the speed of which is governed by the character's individual "Guts" stat. Side effects like CriticalExistenceFailure do not trigger based on the raw damage a character has received, but the value that's currently shown on their meter instead. If the battle is won or the character is healed before the counter reaches zero, the damage stops.
* In the original ''VideoGame/{{Gauntlet}}'', the players' HP decreased at a constant rate throughout the game. The only means to replenish HP? [[WizardNeedsFoodBadly Food items]] in various levels, or [[BribingYourWayToVictory putting more coins in the machine]].
* In ''VideoGame/IMissTheSunrise'', during certain boss missions, you can place your secondary fleets on certain tiles to gain "fire support" from them, causing a small but reliable amount of damage to the boss per turn.
* ''VideoGame/KingdomOfLoathing'' has various items, pieces of equipment and statuses that inflict [[http://kol.coldfront.net/thekolwiki/index.php/Passive_Damage "passive damage"]] over time.
* ''VideoGame/OdinSphere'', in addition to its set of StandardStatusEffects, has fire and ice levels which sap 1% of your character's HP at regular intervals unless you drink an appropriate curing potion beforehand (or have elemental protection equipped).
* Being a snake {{Youkai}}, all of Kiyo-hime's attacks in ''Onmyōji'' deal this as well as lower the opponents' armor.
* The ''VideoGame/{{Pokemon}}'' series has many ways to inflict Damage Over Time beyond its standard "Poison" and "Burn" statuses, and many of these can even be combined:
** If a Ghost-type uses Curse, the opponent receives significant damage (1/4 max HP) per turn, the largest amount of damage in the system.
** Hazardous weather like Sandstorm or Hail inflicts 1/16th damage on most elemental types.
** Certain abilities can also cause damage (or, inversely, healing) over time during specific weather conditions: Dry Skin damages during intense sunlight, Rain Dish and Ice Body heal during heavy rain or hailstorms, respectively. Solar Power also causes damage during intense sunlight, but with the tradeoff of boosted attack power.
** In ''VideoGame/PokemonXDGaleOfDarkness'', Shadow Pokemon who enter Reverse Mode in battle sustain damage per turn, as do non-Shadow Pokemon when subjected to Shadow Sky weather.
** Sleeping Pokemon receive damage while subjected to Nightmare status, or similarly, the [[SignatureMove Bad Dreams ability]] of legendary Pokemon Darkrai.
** The Grass-type move Leech Seed not only inflicts Damage Over Time on an opponent, it also restores the user's HP by the amount drained.
** The Sticky Barb item inflicts damage-over-time on whichever Pokemon holds it, but can be passed from user to opponent by moves involving physical contact. Similarly, the Black Sludge item deals damage-over-time to any Pokemon holding it that isn't a Poison-type (those get healed instead).
* In ''[[VideoGame/PrinceOfPersiaWarriorWithin Prince of Persia: Warrior Within]]'' and ''[[VideoGame/PrinceOfPersiaTheTwoThrones The Two Thrones]]'', the player slowly loses health while playing as the Sand Wraith or the Dark Prince.
* The hallmark ability of the [[PyroManiac Pyro]] class in ''VideoGame/TeamFortress2'' is the ability to set opponents on fire with their flamethrower. Some melee weapons can inflict a "bleeding" status that also causes damage over time.
* ''VideoGame/WorldOfWarcraft'':
** The Priest's Shadow specialization relies heavily on damage over time spells such as Shadow Word: Pain, Devouring Plague, Vampiric Touch and the channelled Mind Flay, with Shadow Word: Death, Mind Blast and Mind Spike being complementary direct damage spells, however Shadow Word: Pain refreshes (through talents) its cooldown whenever Mind Flay is channelled. Depending on the spell haste of the player's character, additional damage can occur in the same length of time as the original spell, particularly observed while channelling Mind Flay.
** The "Warlock" class is primarily built around skills that cause damage over time, especially if specialized in Affliction. In ''Mists Of Pandaria'', when a warlock chooses an Affliction specialization, Shadow Bolt, previously their main direct damage spell, transforms into Malefic Grasp, a channeled damage over time spell that causes their other damage over time spells to hit additional times. Affliction Warlocks do still have Haunt for direct damage, but that spell requires a more limited resource and thus can't be used often.
** Feral Cat Druids deal damage primarily through Rake and Rip, which make the target bleed in a similar way to a Warlock [=DoT=]. [[DifficultButAwesome They're the hardest DPS spec to master, but deal insane damage when done right.]]
** Balance Druids have Moonfire and Insect Swarm that use this mechanic to maintain and bolster their DPS. With ''Mists of Pandaria'', Insect Swarm was removed; but Sunfire was changed to a unique spell instead of being the Solar aspect of Moonfire automatically during the respective Eclipse shift.
** Starting in ''Cataclysm'', Fire Mages rely much more on damage over time, utilizing Living Bomb, Pyroblast, Ignite, Combustion (which grows more powerful the more damage is about to be done by the previous three), a talent which allows Fire Blast to spread the previously mentioned effects to any other opponents in range, and Flamestrike.
** While not relying entirely on damage over time effects, a good chunk of damage done by Assassination Rogues is dealt via Deadly Poison and Venomous Wounds, which has a chance to hit when the bleed Rupture deals damage to a poisoned target.
* ''VideoGame/DungeonsOfDredmor'' includes a variety of effects that cause damage over time, including but not limited to Slimeburst Traps, Acid Burns, Curse of the Golden Ratio, Recursive Curse, and the special ability of the Golden Crossbow. There's also an even wider variety of AreaOfEffect spells that persist over several turns and deal constant damage to anything in range--these ones tend to be very effective for dispatching large groups of enemies.
* In ''VideoGame/{{Xenoblade}}'', any arts of the fire, ice, or earth elements will leave behind a burn, chill, or poison debuff on the victim that causes gradual damage. Some physical arts also leave a bleeding effect. In all cases, the gradual damage dealt is based on how much the initial attack hit for, which can result in some crazy numbers once damage multipliers from gems, skills, and chain attacks come into play.
* The Firebug class in ''VideoGame/KillingFloor'' has a variety of fire weapons, all of which deal fire damage over time.
* ''VideoGame/StarTrekOnline'' features plasma weapons, which have a chance to set the molecules of a vehicle on fire.
* ''VideoGame/{{SolForge}}'' has a poison status effect that does this, somewhat unusually given [[CardBattleGame its genre]].
* The ''[[VideoGame/{{STALKER}} S.T.A.L.K.E.R.]]'' series has radiation (which comes from radioactive artifacts or trekking through irradiated zones), hemorrhage (bleeding, caused by pretty much any injury) and hunger (self-explanatory). Pick your poison, and don't forget your bandages, rad purge drugs and bread on the way out to the Zone.
* In ''VideoGame/{{Undertale}}'', this is part of what makes the battle with the [[VillainProtagonist Genocide Run]] final boss, [[spoiler:Sans the Skeleton,]] so grueling. His attacks deal only 1 damage in theory, but they don't trigger MercyInvincibility and thus hit for [[DeathOfAThousandCuts 1 damage every frame you are in contact with them]]... and on top of that, even when you're no longer in contact with them, they leave a slow damage over time effect (which turns part of your life bar purple, so you can see exactly how much health you will lose). The more you get hit, the longer the damage over time effect lasts, too. [[VideoGameCrueltyPunishment That's the feeling of your sins crawling on your back.]]
* In ''VideoGame/GrimDawn'', almost all form of attacks have a damage over time variant: physical (internal trauma), fire (burn), cold (frostburn), lightning (electrocute), acid (poison), vitality (vitality decay) and bleeding.
* ''VideoGame/DarkestDungeon'' features Bleed and Blight. Mechanics-wise, they're the same thing - a certain amount of damage grouped in stacks that tic down over 3 turns (5 if it lands during a {{crit|iticalHit}} attack); stacks overlap but tic down individually, and both types can be stacked together) -, the difference being who or what is resistant or weak to either. Resistance to both can be buffed or debuffed.
* The [[NamesToRunAwayFromReallyFast Defiler]] demon in ''VideoGame/NexusClash'' wields a powerful poison that deals more lingering damage the more powerful the target is and persists forever until it is directly healed, even if the target ''dies'' and respawns. There's also a less powerful and less persistent version that literally anyone with the right magic item can use.
* In ''VideoGame/PathOfExile'' damage over time comes from StandardStatusEffects like poison, bleed, and burning, as well as virulent magic and swirling vortices of ice. Because damage over time occurs as continuous HP loss rather than by ticks it is not considered to hit, which has both disadvantages [[labelnote: note]]cannot CriticalHit, cannot leech, cannot apply effects[[/labelnote]] and advantages [[labelnote: note]]cannot be reflected, blocked, or dodged, can be exploited with [[AdaptiveAbility Elemental Equilibrium]][[/labelnote]].
* In ''VideoGame/{{Fallout 4}}'', Bleed, [[KillItWithFire Burn]], and Poison are all effects that inflict damage over time. Bleed is especially potent, as it's the one damage type that effects all enemies regardless of type (yes, even robots are vulnerable to it) and there are no resistances or immunities to the damage. A few melee weapons can be modded to inflict Bleed damage while [[VideoGameFlamethrowersSuck flamethrowers]] and sometimes lasers can set targets on fire. There are also legendary weapon effects that can cause Bleed, Burn, and Poison damage over time: Poison is almost completely useless because of how many enemies are immune to it, but a Wounding shotgun is a GameBreaker since each individual pellet that hits a target will cause the Bleeding damage.
* In ''VideoGame/WorldOfTanks'', any vehicle that takes damage to its fuel tank or engine has a chance of catching fire. Unless they've got an equipped fire extinguisher, they're likely to take massive damage and have many other components on the tank damaged before the fire goes out.
* In ''VideoGame/MassEffect3'', the Dark Channel power slowly damages enemies over time, with the added effect of spreading to a nearby enemy when the original target dies.