The “generic” type, meant to represent the simplest ideas. Basic punches, certain small energy projectiles, stuff like that.

A very slight misnomer, this type is meant to represent all things sharp. This includes not only serrated objects (scissors, saws, swords), but pointed ones (needles, spears).

Represents exploding weaponry. Usually means bombs and grenades, though certain other bursts of force might end up with this type as well.

Represents fire and heat.

Represents electricity, including lightning.

Represents the flow of time. This often shows itself in manipulating time to change speed or move backwards, though time has also been shown concentrated into a form of energy.

Represents many things that come from the earth, like soil, stones, and fossil fuels. Also represents things designed to dig into the earth, like drills.

Represents air. Clouds, tornadoes, hurricanes, vacuums, propellers…if it’s in the air or pushes air around, there’s a good chance it’s this element.

Represents water of all kinds (waterfalls, tidal waves, bubbles), and sometimes even other liquids (such as corrosive acid, or slime).

Represents things (people included) that can move fast, are lightweight, or both.

Represents plant life and fungi, and sometimes fauna.

Most obviously represents missiles, but can also represent other forms of ballistic projectiles, especially if they wouldn’t fit under Explode or Cutter alone.

Represents crystals, gems, glass, and other kinds of luminescent minerals. On occasion, it may be used to represent light itself.

Represents darkness, and sometimes illusion. Note that not all that’s dark is evil.

Represents that which is found in outer space, such as stars, black holes, and meteors. May sometimes be used for stranger abstract ideas that are hard to describe.

Represents shields. Is usually paired with another element.

Represents lasers (especially as pop culture portrays them), as well as plasma.

In Mega Man RPG Prototype, this type represents an innate power to copy the powers of others. This is true in Chaos Zone as well, though it expands the definition to include duplication of objects in general, and sometimes copying others in a more mundane sense.

In Mega Man RPG Prototype, this element is very rare, and not considered one of the main 20 regardless of its use in gameplay. It represents a unique, corruptive form of darkness distinct from the Shadow element.
In Chaos Zone, this element is used to represent the concept of nothingness, often in a dark or evil context.

In Mega Man RPG Prototype, this element is used to show the player’s health.
In Chaos Zone, this element is sometimes used to show healing, or to show a nondescript form of “energy” being used as a superpower.

In Mega Man RPG Prototype, this element is used to show how much weapon energy the player has left. Most abilities require the use of weapon energy.
In Chaos Zone, this element is occasionally used to represent forms of weaponry, especially if the weaponry in question is notable. For example, certain attacks called “Spell Cards” are consistently given Weapons as one of their elements, the Weapons element representing the use of a Spell Card instead of just any old ability.

In Mega Man RPG Prototype, this element is used to indicate the player’s attack stat (which affects how much damage they deal).
In Chaos Zone, this element is sometimes used for general forms of attack in place of Neutral.

In Mega Man RPG Prototype, this element is used to indicate the player’s defense stat (which affects how much damage is reduced from an attack).
In Chaos Zone, this element is used for things that can defend oneself, especially if it’s more abstract than what the Shield element covers.

In Mega Man RPG Prototype, this element is used to indicate the player’s speed stat (which affects who acts first).
In Chaos Zone, this element is sometimes used for abilities that involve speed, in place of the Swift element.

In Mega Man RPG Prototype, this element is used to indicate the player’s “experience points”, which indicate how close they are to increasing their “level”.
Chaos Zone doesn’t really have a definitive definition for what this element is; my writing specifically uses it to define “experience” in the broader definition of events and concepts that have been lived through; for this reason, I tend to like using it as a type for powerful finishing moves that characters don’t use until they’ve been through a lot.

In Mega Man RPG Prototype, this element is used to indicate the player’s level (which indicates how powerful they are overall).
Chaos Zone doesn’t really have a definitive definition for what this element is; while several characters have used it, the meaning behind the use has varied between them.

In Mega Man RPG Prototype, this element is used to indicate if a battlefield has modified the power of healing moves.
In Chaos Zone, this element is sometimes used for abilities that have healing powers and/or other forms of restorative power.

In Mega Man RPG Prototype, this element is used to indicate if a battlefield has modified the damage characters deal (as an additional modifier alongside attack and defense)
In Chaos Zone, this element is sometimes used to represent the basic concept of damage and/or pain, which may show itself in a similar manner to how the Attack element is used.

In Mega Man RPG Prototype, this element is used to indicate if something is associated with the character Dr. Thomas Light.
In Chaos Zone, this element is most often used to represent literal light, though this is not the universal use for it, and some may find other contexts to use it for.

In Mega Man RPG Prototype, this element is used to indicate if something is associated with the character Dr. Albert Wily.
In Chaos Zone, this element has seen very little use, though what little use it has seen implies an association with malice (likely stemming from Dr. Wily being the main villain of the Classic Mega Man series)

“None” is actually the name for the Neutral element in the code of Mega Man RPG Prototype, and to match this, typing “None” was the only intended way to display the Neutral element on the forums at first. While the code of the game itself (to my knowledge) hasn’t changed, “Neutral” and “None” are now both ways to display the Neutral element on the website.
In Chaos Zone, the None element (which has become distinct from Neutral) has come to represent nothingness in a less negative light than the Empty element. While I am unsure how other users see the type, I personally treat None as representing a “neutral” form of nothingness, neither positive nor negative.

Inventor unknown. Like None, this element represents the concept of nothingness in a less malicious sense than Empty. While I am unsure how other users see the type, I personally treat Null as representing a more “positive” form of nothingness.

Invented by RotomSlashBlast. Represents the use of sound, such as through song or echolocation.

Invented by Beta Shadow. Represents paranormal entities, such as ghosts.

Invented by Beta Shadow. Represents psychic powers.

Invented by Beta Shadow. Represents metal, independently of types such as Cutter or Impact.

Invented by Beta Shadow. The concept it represents is somewhat vague, though it seems to have a connection to dragons in some form.

Invented by Beta Shadow. Represents the manipulation of reality as distinct from Time or Space.

Invented by Beta Shadow. Represents magic, especially in mystical contexts, and situations where the magic isn’t of a clear element besides itself.

Invented by RotomSlashBlast. Represents poison and venom.

Inventor unknown. Represents light when the Light element is not used for such.

Invented by GammaGhost/GammaGuardian/Radiated Wraith. Represents a special idea of hope being used as energy.

Invented by TheHighTower. Represents the use of power from the sun (in a more specialized context than, say Flame).

Invented by me. Represents abilities that constrict the opponent in some way, such as by grabbing them or entangling them.

Invented by Beta Shadow. Represents the use of “Chaos Energy”, a kind of energy found within special objects from the Sonic the Hedgehog franchise.

Invented by me. Represents powers derived from one’s physical body, such as their flesh or their circulatory system.

Invented by Beta Shadow. Represents the use of Limited.

Invented by me. Represents powers derived from animals (carnivorous bites and scratches, insect-like stinging, etc.), and occasionally the manipulation of animals themselves (though this is still mostly saved for Nature).

Invented by RedBomber. Represents power formed from anger.

Invented by me. Represents the ability to create things without tools, as well as the ability to change one’s physical form through biological means.