Trainers » Wally
Wally says "you can use this card on your first turn or on a Pokemon that was put into play this turn". Does that mean I can use Wally on the very first turn of the game when I am not allowed to play Supporter cards?
No, Wally does not override the game rule of the player going first not being able to play Supporter cards on their first turn. You can only play Wally on your first turn if you are going second.
Source: TPCi Rules Team (2021-02-04)
Trainers » Roxie
Can you play Roxie to discard Pokemon from your hand if you have no cards in your deck?
No, you cannot.
Source: TPCi Rules Team (2021-02-04)
Trainers » Heinrich Eich
Due to an error in naming the German version of the card for Samson Eich (aka "Samson Oak"), the name of this card will be changed. The original name for this Supporter card was "Samson Eich". The card name must be changed to match the original name of the character, which should fall in line with the animation and video game series. The new card name for Samson Eich will be "Heinrich Eich".
Trainers » Gewöhnliche Angel
Due to an error in the German version of the card text for Gewöhnliche Angel (aka "Ordinary Rod"), the first part of the card will be changed. The original text for the Item card says, "Wähle 1 aus:" ("Choose 1:"); the new text for Gewöhnliche Angel will say, "Wähle 1 oder beides aus:" ("Choose 1 or both:").
Source: TPCi Announcements (2020-03-12) [https://www.pokemon.com/de/pokemon-news/erratum-gewoehnliche-angel-im-pokemon-sammelkartenspiel/]; TPCi Rules Team (2021-02-04)
Trainers » Drone Rotom
Drone Rotom says, "Your opponent reveals their hand. If they do, look at the top card of your opponent's deck." But what happens if the opponent doesn't have any cards in their hand?
If there are no cards in your opponent's hand, you can't play Drone Rotom in the first place.
Source: TPCi Rules Team (2021-01-21)
Trainers » Devolution Spray Z | Abilities » Top Entry
If I play a Pokemon with the "Top Entry" Ability and it goes to the bench as a Stage 1, what happens if I then use Devolution Spray Z?
You can't use Devolution Spray Z on it since although it is an "Evolution Pokemon", it is not Evolved because there is no Basic underneath it. Either you can't play the card, or if it has already been played (it's no longer in the hand) another target will have to be chosen. If there are no other legal targets, then the play has to be reversed.
Source: TPCi Rules Team (2021-01-21)
Attacks » Devilish Hands GX | Attacks » Electro Rain | Trainers » Telescopic Sight
When using Alolan Raichu's "Electro Rain" attack or Hoopa GX's "Devilish Hands GX" attack with a Telescopic Sight tool attached, would Telescopic Sight boost the damage to Pokemon-GX and Pokemon-V each and every time I choose that Pokemon?
Per the rule book you make all your choices first, calculate the damage, then apply modifiers (such as Telescopic Sight), and then apply damage to the chosen Pokemon. So you would not get to add +30 more than once if you choose the same Pokemon again and again; however if you choose multiple Pokemon-GX or Pokemon-V, you would get to add +30 to each of those.
Source: TPCi Rules Team (2020-12-10)
Trainers » Lysandre {*} | Abilities » Shifty Substitution
If I play Lysandre {*} when my opponent has Shiftry's "Shifty Substitution" Ability in effect, does Lysandre {*} go to the Lost Zone or not after it has been played?
Shifty Substitution does not affect the Prism Star rule, so Lysandre {*} would go to the Lost Zone.
Source: TPCi Rules Team (2020-12-10)