The top half of a Data Monster's border is mettalic gray, while the bottom half has the border color of whichever sub-types a given Data Monster has. Its effect box is split into a Data Effect (which contains an additional stat named Compatibility Margin), and an ordinary monster effect.
Once per turn, during their Main Phases, for each monster they control, each player can Inject and Eject a Data Monster from a given monster they control. Injection means placing a Data Monster from the hand underneath a monster on the field, and Ejection means returning that Data Monster to the hand. There are a few rules regarding Injection and Ejection:
- To Inject a Data Monster A into a monster B on the field, the Level of B must be within this interval:
- If the Data Monster's Margin is Negative: [Level of A - |Compatibility Margin of A|; Level of A]
- If the Data Monster's Margin is Positive: [Level of A; Level of A + Compatibility Margin of A]
- If the Data Monster's Margin is Neutral (0 or ±): [Level of A - |Compatibility Margin of A|; Level of A + |Compatibility Margin of A|]
- Each monster can only be Injected with at most 1 Data Monster at a time.
- If a monster on the field is removed from the field while being Injected with a Data Monster, that Data Monster is sent to the Graveyard.
- When a Data Monster A is injected to a monster B on the field, B gains the Data Effects of A, as long as A is Injected into B. Non-Effect monsters are able to make use of their Injected Data Effects.
- Data Monsters can be Injected into other Data Monsters on the field.