Navi Chips

Navi Chips are a special kind of Battle Chip in the Mega Man Battle Network series that summons the depicted NetNavi to perform their signature attack.

Properties
Navi Chips are be obtained chiefly by defeating their respective Navi (i.e., a ProtoMan Navi Chip is won by defeating ProtoMan). They can also be obtained through the Chip Trader or from other characters during the course of the game. All Navi chips have a 5-star rarity, and with the exception of the first and second Mega Man Battle Network games, where Battle Chip classes did not exist, all Navi Chips are Mega-class, with certain higher level chips being Giga-class. Navi Chips are usually marked with a black star icon on the Custom Screen, however certain chips, especially Giga-class Navi Chips, have other icons, such as the Navi's face. When used, the screen will darkened and the Navi will appear briefly, where they will use their signature attack and disappear.

Depending on the circumstances, the summoned Navi can attack differently. Examples are the player being able to hold the A button to move MetalMan to the enemy before attacking and AquaMan attacking with his Aqua Stream instead of an Aqua Bomb if the player in on the left most middle panel when AquaMan is summoned.

In PvP, Navi Chips can be countered Anti-Navi battle chip and the Beat Navi Customizer Program. The Giga Chip Navi Recycle will replicate a Navi Chip or any Program Advance that uses one.

Levels
Besides Giga-class chips such as Serenade and the the Mega-class Punk chip, Navi Chips come in several different levels, with an increase in attack damage with each subsequent level. One can only obtain higher level chips if they defeat more powerful versions of the Navi they want the chip of. When a Navi is fought in their strongest form, one can obtain the weakest version of their chip by getting a busting level of 1-5, the mid-version chip by getting a busting level of 6-9, and the strongest version by getting a busting level of 10 or S. In certain games, the attack damage of the strongest Navi chip will increase the faster the player can S-rank their opponent.

In the original Mega Man Battle Network, each level was simply number (1, 2, and 3). In Mega Man Battle Network 2 and 3, they were classified by version (V1, V2, and V3), with Battle Network 3 adding in V4 chips as well as Giga-class V5 chips. In Mega Man Battle Network 4, 4.5, and 5, Navi Chip levels were changed (normal, SP, and DS). SP chips can only be used by MegaMan if he is light colored, while DS chips can only be used if MegaMan has a Dark Soul. In Mega Man Battle Network 6, Navi Chips return to three levels (normal, EX, and SP). In Mega Man Network Transmission, there is only one Navi chip per boss. In Rockman.EXE Phantom of Network, Navi chips have four levels (normal, V2, V3, and SP).

Notably, Bass only has normal level Navi chips in the first and second games. Later games feature him only as a Giga-class chip with special designations (i.e. Bass Another, Bass Anomaly, etc.)

Merchandise
Navi Chips were made into real-life toy Battle Chips alongside all other chips from the series from Mega Man Battle Network 4 onward. Special chips called Navi Data Chips are colored chips that unlock the depicted character to be played in Rockman.EXE 4.5: Real Operation as well as the Japanese versions of Battle network 5 and 6.

Anime
The only acknowledgment of Navi Chips within the anime was in the Rockman.EXE Beast+ episode Zero Invasion, where they were mentioned and seen on the screen of the Battle Station. They were never seen, mentioned, or used before or after this however.