Unlike other card types, Z/X Overboost cards are comprised of two cards that were combined as one when they appeared in Square: the upper part (上部 Jōbu) and the lower part (下部 Kabu). The upper part is put into the Dynamis and up to four of them can be put into the Dynamis in addition to the 12 Z/X Extra and/or Shift cards in there. The lower part is prepared separately from the deck and only one can be prepared per deck.
During the game preparation, if a player choose to bring Z/X Overboost cards in their deck, the lower part of a Z/X Overboost is stacked on the backside of the Player card so that the front side of the Z/X Overboost becomes the backside of the Player card. Afterwards, the Player card is put face down on the Player Square as usual.
Like Z/X Extra, Z/X Overboost are also treated as regular Z/X during the game. If a Z/X Overboost would left the Square due to any circumstance, instead the upper part of the Z/X Overboost is put face-up into Dynamis and the lower part of the Z/X Overboost is turned face-down and put back on the Player Square as Player card in Reboot State.
Since Z/X Overboost are comprised of two cards, it simultaneously possess all parameters from both its upper and lower part while in play. Each part possessed their own specific parameter. A face-up upper part of Z/X Overboost in Dynamis, for example, does not count for Level Ability since the parameter for Tribe is only possessed by the lower part.
Make a Z/X Overboost Appear on Square
- Main article: Ignition Overboost
Z/X Overboost can appear on Square by performing the following steps:
- Play the dedicated Event card to perform Ignition Overboost.
- The dedicated Event may specify the name of Z/X for the Player to Ignition Overboost into. For example, you can only Ignition Overboost into a Z/X Overboost with "Azumi" in its card name using "Azumi and Rigel, Oath to the Blue Sky".
- Perform the Ignition Overboost process as the Event resolves. The detailed process is as follows.
- Reveal the lower part of the Z/X Overboost.
- If the lower part of the Z/X Overboost contain the name specified in the text of the dedicated Event card, reveal a face-down upper part of Z/X Overboost with the same name as the lower part from your Dynamis.
- Join the upper part and the lower part together as a single card, and make the Z/X Overboost appear on empty Square except the opponent's Player Square in Reboot State.
All ability and effect possessed, given, or applied to the original Player card will be lost and not carried over to the resulting Z/X Overboost, and vice-versa.
Each player may only control one Z/X Overboost on Square, and cannot perform another Ignition Overboost while they still control a Z/X Overboost on Square. The Ignition Overboost process itself is a part of the game mechanic, and does not count toward the once-per-turn limit of playing Z/X Extra from the Dynamis.
While Z/X Overboost is on Square
The following condition applies to player that control a Z/X Overboost on Square:
- All ability that refer to a specific Player card can refer to the "Player" parameter written in the Z/X Overboost.
- For example, the ability of your "Sword Sniper, Rigel" is still available while you control "Blue Sky Engage, Azumi Kagamihara" on Square.
- If the Z/X Overboost does not possess a written "Player" parameter, the "Player" parameter of that Z/X Overboost will take the "Player" parameter of the original Player card.
- That player may still make a Z/X appear on their empty Player Square.
- That player does not receive any damage. Moreover, the empty Player Square of that player cannot be attacked by the opponent's Z/X.