If Thunder Mountain {*} is in play, does Pikachu & Zekrom GX's "Tag Bolt GX" attack need 5 {L} attached or 6 {L} attached in order to get its bonus effect?
The base energy requirement of the attack is one {L} less for Thunder Mountain {*}, but it does not apply to the additional energy required for its bonus effect. You need 5 {L} attached in order to get the bonus when Thunder Mountain {*} is in play.
Source: TPCi Rules Team (2019-08-01)

Relevant cards

Note: All applicable cards may not be listed below.
SM8_191