A Quick Time Event (QTE), also referred to as an Action Event (アクションイベント,akushon ibento?), is an action sequence in which the progression of the game depends on the button(s) pressed by the player. It first appeared in Resident Evil 4.
In the newest Resident Evil games such as Resident Evil 4 and Resident Evil 5, QTEs play a larger role and now, depending on what you're trying to evade, if you fail the QTE your character will die instantly.
QTEs are used extensively in cutscenes, they are also used to perform context sensitive actions on enemies and the environment. They have become a staple of the franchise and have appeared in every major release since RE4.
These events generally require the player to press certain prompted buttons in a particular order, or perform certain gestures with the gamepad (on the Wii and PlayStation Move), usually within a specified amount of time to guarantee survival. Failure to do so will lead to an instant "Game Over" in most cases or a significant loss of the character's health.
In both Chronicles games, QTEs appear in a few instances depending on the attack the enemy is doing, some QTEs are scripted and will appear every time a certain attack is being made by an enemy, but others will only appear once the player is grabbed by a zombie.
New to Resident Evil 6, certain QTEs now have a small bar to indicate the player's action progress. QTEs are much easier to complete, specially if one is using the Breakout Skill and the prompts will always be the same unless you choose a higher difficulty. They also repeat a lot, for instance, in the beginning of Jake's Chapter 4, the two QTEs in the Motorcycle stage will always be the same no matter what. Additionally, QTEs in Resident Evil 6 also serve as a way to open doors, counter enemy attacks, use certain objects and even to drive vehicles. All QTEs will be automatically completed even if the player fails them by turning on the "auto action button" option in the Game Settings menu. Although if the Amauter difficulty is selected, all QTEs will be successful even if that option is turned off.
The Live Selection and "dodge" features of Resident Evil 3: Nemesis were similar to Quick Time Events but did not require button inputs. However, failing to react in time to these in some instances would cause a loss of health similar to a QTE, such as not choosing an option on the cable car.