Main/Flash of Pain - Television Tropes & Idioms

In many video games, enemies that don't die from one hit will blink a different colour when damaged. Most of the time, it tends to be white, although it may come in different variants, like red.

The Flash of Pain will definitely be used on a boss that is Immune to Flinching, because it conveys that the player's attacks are actually landing damage. Especially important if the boss has a weak point on its body that must be hit in order to cause any damage (in which case usually just the weak part of the enemy will flash). Sometimes the player also flashes in a different color when hit, when the game doesn't feature Mercy Invincibility.

Prolonged flashing may also signify that an enemy has Mercy Invincibility after you have attacked it, in which case you must wait for it to stop flashing before you can damage it again.

A related analogue occurs in first-person videogames, where - because the player is unable to see their own character - if the player takes a hit, the entire screen will flash momentarily to indicate damage.

In some cases when a boss Turns Red, it will look the same as the Flash Of Pain, except it will flash repeatedly on its own.

This trope follows the Rule of Perception, of course, as the Video Game character presumably doesn't see his opponent flashing white for a split second.

Examples:

Action Adventure

The Binding of Isaac has enemies flashing deep red when hit while the player character has a subtle flash and Mercy Invincibility. The multicoloured Champion variants of regular enemies will flash in whatever colour contrasts their body the most.
The enemies in the original Blaster Master games do this.
Both Link and bosses in The Legend of Zelda games.
Lagoon applies this to the player character, Nasir, as well as enemies.
Bosses and enemies in Shantae series either flash when damaged or play a "taking damage" animation.
Snailiad uses this.

Action Game

Enemies with multiple hitpoints and bosses in Tank Force flash white.
Larger enemies, bosses and walls in Heavy Barrel
Bosses blink white in Last Alert.
Skeleton Krew had certain obstacles moving along a set path that displayed the same flash that enemies did when shot. However, those obstacles are really indestructible, and the flash is meaningless in their case.

Beat 'em Up

Many Konami games do this when bosses are hit combined with turning red such as Teenage Mutant Ninja Turtles: The Arcade Game, The Simpsons, and X-Men.

Fighting Game

This shows up occasionally in the Capcom vs. Whatever series.
- In Marvel vs. Capcom, certain characters, like the Hulk, could take a shot without flinching, flashing red to show they did this. Hidden character Mecha-Zangief could take an infinite number of shots at the cost of being unable to block.
- In Tatsunoko vs. Capcom, the giants and Yami do. This is because giant characters, who fight alone, don't flinch when damaged (as compensation for not having a partner).

First-Person Shooter

In the Marathon trilogy, S'pht compilers not only flash into static when they're hit, that's also their death animation.

Multiple genres

The enemies in platforming parts of ActRaiser blink red and white when hit. Even those which require single hit, blink red before exploding. In town building parts, the enemies blink white when hit.
Enemies and bosses in Spin Master blink red when hit.
Vice: Project Doom: The enemies blink yellow when hit.

Platform Game

Bosses in the first Adventure Island game blink purple when hit. Subsequent games use white color instead.
The enemies in Batman: Return of the Joker for the NES blink red and crates blink white after getting hit.
Strangely enough, enemies and bosses in Bug! only flash red in the Sega Saturn version. The PC version averts this.
All of the Contra games have the enemies flash when your shots are dealing damage, but in Contra: Hard Corps the bosses and minibosses go through an almost psychedelic pattern of colors while taking damage. It's especially unsettling with the larger bosses.
Enemies in Dynamite Headdy always flash white with the same little sound effect whenever they take damage without dying.
Gish flashes red in his game when he is damaged.
The enemies in Journey To Silius flash pink after getting hit for some reason.
Most bosses in Kirby games, along with some stronger enemies.
The Mega Man series of games: regular enemies with flash invisible for about 2 frames, while bosses and Mega Man himself flash white.
Many enemies in Metroid. Sometimes, a boss will flash yellow when an attack will just stun it, and red when attacks start to damage it for real.
If a boss in Moon Crystal is hit, the entire screen flashes white.
Hayate will flash white in Ninja Senki, but other enemies don't flash much.
Enemies in Ratchet & Clank flash red when damaged.
Bosses and some other things with multiple hitpoints seem to blink white in 2D Sonic the Hedgehog games.
- Any fight with Robotnik changes his sprite, making him look directly at the player, mouth open screaming with a more frayed mustache upon being hit.
One of the few Mario examples, are the bosses in Super Mario Bros. 2 a.k.a Super Mario USA mainly due to it not originally being a Mario game. Enemies requiring multiple hits will flash in the dominant color of the character you're using.

Real-Time Strategy

Z has robots that flash white when hit by a bullet. Both for the robots you control and the enemy, presumably to help you notice when your units are being attack by something slightly off screen.

Role-Playing Game

Most enemies in Chrono Trigger.
In many of the Final Fantasy games, enemies will "flash" or otherwise demonstrate that they'd been attacked with a special effect. Even as early as the original Final Fantasy I for NES, the flashes would be color-coordinated to the type of weapon or spell used.
The Kooma Panda and Ursa Circus dream eaters in Kingdom Hearts 3D flash red when struck with weak attacks to indicate that they're Immune to Flinching. Oddly, the multitudes of other enemies with the same ability don't flash at all.
Mass Effect 2 has a variation: your squadmates' status bar icons flash red when they take health damage, rather than the squadmates themselves.

Shoot 'em Up

Bosses and some enemies in arcade Bells And Whistles flash when hit.
Enemies in Dogyuun flash yellow when damaged.
Enemies in DonPachi series have been known to flash different color depending on game. In one game, they flash blue while in the other, they flash gold color.
Characters in Mushihime-sama series flash yellow though.
Enemies in Radiant Silvergun flash white when hit.
In Spheres Of Chaos, it's possible to add an option for the whole screen to flash when a black hole is hit.
Bosses in Super Space Invaders / Majestic Twelve flash when hit on a vulnerable area.
Enemies and bosses in Zanac Neo.
Flashes of pain often happen in Zero Wing.