Elements

Just like every other Megaman series, there are weaknesses and strengths to attacks. In the Battle Network franchise, there is a set of elements that are attached to chips and viruses. In MegaMan Battle Network 1,2, and 3, there are 5 elements: Fire, Aqua, Elec, Wood, and null, or no element. If a viruses element was weak against a chip used, the virus will take 2x damage. As the series progressed, more elements were added. This was needed because in the 4th and 5th editions of the game (MegaMan Battle Network 4 and 5), the double soul ability that replaced style change requires the sacrifice of a chip of the same element as the double soul being used. At the end of the series in MegaMan Battle Network 6, there are a total of nine elements. All the elements and their attributes are listed below.

Fire/Flame
Strong against Wood, weak against Aqua.

Abilities

Wildfire: If a virus or navi is standing on a grass panel, fire attacks do double damage regardless of the attribute of the Navi/virus. (all games)

Lava immunity: Fire attributed Navis/viruses do not take damage from lava panels. (BN 1,2,3,4)

Lava absorb: While using Firesoul, Megaman will recover 50 HP every time he steps on a lava panel, but this turns the panel back to normal. (BN 4 only)

Styles(MMBN 2,3)

A fire attribute style will have the prefix "Heat".

Souls(MMBN 4 and 5)

Firesoul (Fireman) obtained in MMBN4 Red Sun Napalmsoul(Napalmman) obtained in MMBN5 Team Protoman.

Crosses(MMBN 6)

Heatcross (Heatman) obtained in Gregar version.

Chargecross (Chargeman) obtained in Gregar version.

Bosses
 * Fireman.EXE (BN1, BN4 Red Sun)
 * Heatman.EXE (BN2, BN6 Gregar)
 * Napalmman.EXE (BN2, BN5 Team Protoman)
 * Flameman.EXE (BN3)
 * Burnman/Burnerman.EXE (BN4)
 * Blastman.EXE (BN6)

Aqua/Water
Strong against Fire, weak against Elec

Abilities

No Slide: A water attributed Navi/virus will not slide on ice panels. (all games)

Moisture Freeze: If hit by an Aqua attack while on an ice panel, a Navi/virus will be frozen and the ice panel will turn back to a normal panel. (BN 6 only)

Styles

An Aqua attribute style will have the prefix "Aqua".

Souls

Aqua/Spoutsoul (Aqua/Spoutman) obtained in MMBN4 Blue Moon.

Toadsoul (Toadman) obtained in MMBN5 Team Colonel.

Crosses

Aqua/Spoutcross (Aqua/Spoutman) obtained in Falzar version.

Bosses
 * Iceman.EXE (BN1)
 * Sharkman.EXE (BN1)
 * Freezeman.EXE (BN2)
 * Toadman.EXE (BN2, BN5 Team Colonel)
 * Bubbleman.EXE (BN3)
 * Coldman.EXE (BN4)
 * Aqua/Spoutman.EXE (BN4, BN6)
 * Blizzardman.EXE (BN5)
 * Diveman.EXE (BN6)

Elec
Strong against Aqua, weak against Wood.

Abilities

Conductor: When a Navi/virus is standing on an Ice panel, an Elec attack will do 2x damage regardless of the attribute of the Navi/virus. (all except BN6)

Styles

An Elec style will have the prefix "Elec".

Souls

Thundersoul (Thunderman) obtained in MMBN4 Red Sun.

Crosses

Eleccross (Elecman) obtained in Gregar version.

Bosses
 * Elecman.EXE (BN1, BN6 Gregar)
 * Magnetman.EXE (BN2, BN5 Team Protoman)
 * Flashman.EXE (BN3)
 * Sparkman.EXE (BN4)
 * Thunderman.EXE (BN2, BN4 Red Sun)
 * Cloudman.EXE (BN5)

Wood
Strong against Elec, weak against Fire.

Abilities

Lifeheal: When a Wood attribute Navi/virus stands on a Grass panel, they will regain HP.

Styles

A Wood style will have the prefix "Wood".

Souls

Woodsoul (Woodman) obtained in MMBN4 Blue Moon.

Tomahawksou l(Tomahawkman) obtained in MMBN5 Team Colonel.

Crosses

Tomahawkcross (Tomahawkman) obtained in Falzar version.

Bosses
 * Woodman.EXE (BN1, BN4 Blue Moon)
 * Planetman.EXE (BN2)
 * Snakeman.EXE (BN2)
 * Plantman.EXE (BN3)
 * Tomahawkman.EXE (BN5 Team Colonel, BN6 Falzar)

Null/No element
This element has no weaknesses or strengths.

Abilities

None.

Styles

Normalstyle: The basic Megaman style, no special abilites.

Hubstyle: a style obtainable only in MMBN2.

Souls

None.

Crosses

None.

Bosses
 * Gutsman.EXE (BN1, BN2, BN3)
 * Protoman.EXE (BN1, BN2, BN3, BN6) as null
 * Numberman.EXE (BN1) as null
 * Bombman.EXE (BN1)
 * Colorman.EXE (BN1)
 * Stoneman.EXE (BN1)
 * Magicman.EXE (BN1)
 * Lifevirus.EXE (BN1)
 * Airman.EXE (BN2)
 * Quickman.EXE (BN2)
 * Knightman.EXE (BN2) as null
 * Shadowman.EXE (BN2) as null
 * Cutman.EXE (BN2)
 * Shadowman.EXE (BN2) as null
 * Gateman.EXE (BN2)
 * Bass.EXE (BN2, BN3, BN4, BN5, BN6)
 * Gospel Bug Beast (BN2)
 * Beastman.EXE (BN3)
 * Metalman.EXE (BN3) as null
 * Kingman.EXE (BN3)
 * Desertman.EXE (BN3)
 * Mistman.EXE (BN3)
 * Darkman.EXE (BN3)
 * Serenade.EXE (BN3)
 * Punk.EXE (BN3)
 * Alpha (BN3)
 * Shademan.EXE (BN4, BN5)
 * MegamanDS.EXE (BN4)
 * Laserman.EXE (BN4)
 * Normalnavi.EXE (BN4)
 * Heelnavi.EXE (BN4)
 * Topman.EXE (BN4)
 * Kendoman.EXE (BN4)
 * Duo.EXE (BN4)
 * Gridman.EXE (BN5)
 * Darkmega.EXE (BN5)
 * Cosmoman.EXE (BN5)
 * Nebula Gray (BN5)
 * Elementman.EXE (BN6)
 * Judgeman.EXE (BN6)
 * Circusman.EXE (BN6)
 * G-Beast (BN6 Gregar)
 * F-Beast (BN6 Falzar)
 * Gregar.EXE (BN6 (Gregar)
 * Falzar.EXE (BN6 Falzar)

Recov/Recovery (BN4 and 5 only)
This element was added in Battle Network 4 and 5 to provide a sacrifice chip for double souls.

It does not have a weakness or strength, as it is only applied to recovery chips.

Abilities

None.

Souls

Rollsoul (Roll) obtained in MMBN4 Red Sun.

Meddysoul (Meddy) obtained in MMBN5 Team Protoman.

Bosses
 * Roll.EXE (BN4 Red Sun)
 * Meddy.EXE (BN5 Team Protoman)

Invisible/Invis (BN4 and 5 only)
This element was added in Battle Network 4 to the chips "Invis" and "Popup".

It was added to provide a sacrifice for Searchsoul and Shadowsoul. This element has no weaknesses.

Abilities

An Invis element chip will make the user untouchable by non-piercing attacks for an amount of time that depends on the chip used.

Souls

Searchsoul (Searchman) obtained in MMBN4 Red Sun.

Shadowsoul (Shadowman) obtained in MMBN5 Team Colonel.

Bosses

Searchman.EXE (BN4 Red Sun) as Invis

Shadowman.EXE (BN5 Team Colonel) as Invis

+/- (BN4 and BN5 only)
This element was added to provide a sacrifice for Numbersoul. It is applied to chips that add effects and damage to chips.

This element has no weaknesses.

Abilities

A +/- element chip will add damage or an effect to a chip selected before it on the custom screen.

Souls

Numbersoul (Numberman) obtained in MMBN4 Blue Moon and MMBN5 Team Colonel.

Bosses

Numberman.EXE (BN4, BN5) as +/-

Ground Cracking (BN4 only)
This element was added to prvide a sacrifice for Guts soul. It was taken out because it had no purpose other than that.

This element has no weaknesses.

Abilities

N/A

Souls

Gutssoul (Gutsman) otained in MMBN4 Red Sun.

Bosses

Gutsman.EXE (BN4 Red Sun) as Ground Cracking

Breaker (BN4, BN5, BN6)
This element was added to provide a sacrifice for Metal soul, but was kept in BN6 as an element for crosses.

This element is weak against Cursor and strong against Sword.

Abilities

SuperArmor: A Breaker attributed Navi/virus will not flinch.

Pierce: A Breaker element attack will pierce armor, guards, and invisibility.

Souls

Metalsoul (Metalman) obtained in MMBN4 Blue Moon

Knightsoul (Knightman) obtained in MMBN5 Team Colonel

Crosses

Groundcross (Groundman) obtained in Falzar version.

Dustcross (Dustman) obtained in Falzar version.

Bosses

Metalman.EXE (BN4 Blue Moon) as Breaker

Knightman.EXE (BN5 Team Colonel) as Breaker

Groundman.EXE (BN6 Falzar)

Dustman.EXE (BN6 Falzar)

Cursor (BN5, BN6)
This element was added in BN5 as a replacement sacrifice for Search soul, since the Invis element was taken by Shadow soul.

This element is weak against Wind and strong against Breaker.