Invincibility (video game terminology)
Invincibility is a video game term and mechanic used in a wide variety of games. Invincibility is typically used as a blanket term to describe a variety of ways in which the player's character cannot be damaged by enemies or hazards, however, there are multiple variations of invincibility and each pertains to a different game mechanic. I differentiate between three distinct forms: invincible, invulnerable, and indestructible.
Type 1: Invincibility
The player's character is not only immune to damage from colliding with enemies, but also hurts the enemies they touch. This type is what most people think of when they picture invincibility in a video game and it is sometimes called "death touch." Invincibility typically only lasts for a brief period of time and there is usually both an auditory and visual cue notifying the player that their character is invincible.
How it's used: Invincibility is typically awarded as a special power-up bonus. It can be awarded randomly, but it is far more likely to be placed by a map designer in a specific location to help the player get through a particularly difficult section. Invincibility power-ups are frequently hidden and serve as a reward to observant or tenacious players.
- Pac-Man - When Pac-Man eats a power pellet, he becomes invincible for a short period of time.
- Super C - The eagle with a B gives the character an energy barrier making them invincible.
- Super Mario Bros. - The starman power-up is an iconic invincible power-up.
Type 2: Invulnerability
The player's character cannot be damaged and enemies and their projectiles will pass right through the character. Audio cues are rare for invulnerability, but a visual cue is almost always applied; usually the character will flicker.
How it's used: Invulnerability can be awarded as a power-up, but it is far more common to see it used after the player takes a hit. In this case, invulnerability is used as a mechanic to solve a problem with enemy collision. Video games are usually programmed to check for collisions between the player's character and enemies several times a second, however, if the character were to lose health on each one of these checks, even a seemingly short collision with an enemy would do a lot of damage. Some early video games were programmed this way, much to the chagrin of the player. This problem can easily be solved with enemy projectiles because they can be made to disappear the moment they hit the player, but making a large enemy disappear when it hits the player looks silly, so game designers started making the character invulnerable for just enough time to let the player process the attack and move to safety before becoming vulnerable again.
Examples: Thousands of games use invulnerability as a mechanic to prevent multiple collisions, but the following games also use it as a power-up:
- Castlevania - The invisibility potion lets you walk through enemies without taking damage.
- The Legend of Zelda - The magic clock makes Link immune to damage and lets him walk through enemies.
Type 3: Indestructibility
The player's character still collides with enemies and attacks still knock the character back, but the character doesn't actually lose any health. This is distinct from invulnerability because it alters game play. When a player's character is invincible or invulnerable, they can simply run though the level with ease, but an indestructible character's movement is still impeded, so the player must still avoid or destroy enemies to make progress. This is the least common of the three types and is only employed in a handful of games. Being indestructible typically has a visual cue, and sometimes an auditory cue.
How it's used: Indestructibility is typically given as a temporary power-up to help a player pass though a difficult section. Any cheat code which grants the player infinite hit points (while still letting them take hits) will also act as indestructibility.
- Doom - The green artifact shields against all damage, but enemies can still trap you, and explosions still blow you back.
- Sonic the Hedgehog - The shield monitor makes Sonic indestructible to the next single hit, but Sonic will still be knocked back.
While the three types of invincibility listed above describe the majority used in video games, there are still others. For example, in the game Secret of Mana, characters can wear a barrel which makes them invincible against mundane attacks, but they can still take damage from some magic attacks. Likewise, a game might make a character invincible to projectile attacks, but they may still be damaged from enemy collisions. There are also forms of death that are not typically protected against even while invincible like falling off the screen, being crushed by a wall in a map with forced scrolling, or being telefragged.