Costs

There is no official term for this. This is a fan-term used to describe when an action needs to be performed in order to resolve the rest of the following effect. However, the detailed rulebook specifically lists these effects.
All "costs" are optional, but are required to be done in order to perform the following actions afterwards.
== Effect Structure ==
The three structures are used to define a cost in English:
* "By doing <X>, do <Y>"
* "You may do <X> to <Y>"
* "You may do <Y> by doing <X>"
All three of these are used when defining costs in the Digimon Card Game. There is no substantial difference between the three structures gameplay-wise. However, some cards may be worded "By doing <X>, you may do <Y>" which causes both the cost and the following effect to become optional.
All of these effects are written the same way in Japanese using "By doing <X>, do <Y>".
== General Rules ==
When activating an effect like this, you will choose to perform <X> in order to perform the following <Y>. In all cases performing <X> is optional if you would prefer not to do <Y>. If an effect has a or a similar activation limit, choosing not to pay the cost or being unable to pay the cost will result in the effect not activating.
Additionally, you are allowed to perform <X> even if you would be unable to execute <Y>. If you do so, this will still count towards the or activation limit. But in most cases it is mandatory to perform <Y> after performing <X> unless otherwise specified.
== Rulings ==
== Sources ==
* Detailed Rules Explanation
# Detailed Rules Explanation
# Carddass Email English 12/10/2021: Mummymon Optional Difference