If I have 5 Pokemon on my Bench and Lunatone with "New Moon" Ability and Solrock are in play, what happens if my opponent plays Collapsed Stadium? Would I have to discard any Benched Pokemon or does "New Moon" prevent that?
The effect of Collapsed Stadium is being done to the player's bench size, not to the Pokemon on the bench; so New Moon would not protect them and you would have to discard Benched Pokemon.
Source: TPCi Rules Team (2023-09-07)
Would a Solrock coming into play on the bench receive damage counters from Gapejaw Bog if a Lunatone with "New Moon" Ability is in play but the Ability is not active yet (it requires Solrock to also be in play)? Or what if you put that Lunatone onto the bench while Solrock is already in play?
New Moon activates immediately when it's condition is met, so in either case the 2 damage counters from Gapejaw Bog would be prevented.
Source: TPCi Rules Team (2023-09-07)
If Lost City stadium is in play and Lunatone's "New Moon" Ability is active, what happens if multiple Pokemon including Lunatone & Solrock are KO'd?
All KO's are evaluated simultaneously, so if the New Moon ability was active all KO'd Pokemon would go to the discard pile.
Source: TPCi Rules Team (2023-09-07)
If Grant ends up in my discard pile during the first turn of the game, can I use its effect if I'm going first?
Yes you can. The part about "if this Grant is in your discard pile" is not part of the Supporter's action.
Source: TPCi Rules Team (2023-08-31)
If I have a Klawf ex with "Counterattacking Pincer" Ability and Rugged Helmet attached to it, what happens if it gets damaged by an opponent's attack from a Fusion Strike Pokemon that has a Fusion Strike Energy and a Double Turbo Energy attached to it?
The Counterattacking Pincer ability and Rugged Helmet are triggered simultaneously, so you may choose the order in which they are applied. If you choose the Counterattacking Pincer ability first it will fizzle due to Fusion Strike Energy. However, if you choose to use Rugged Helmet first you can put the Fusion Strike Energy into the opponent's hand and then you can use Counterattacking Pincer to discard the Double Turbo Energy.
Source: TPCi Rules Team (2023-08-31)
If one of my Pokemon was knocked out by an effect of an attack or an Ability, would I still be able to play Letter of Encouragement?
Yes, there is no restriction on how the Pokemon was Knocked Out. However, a KO during Pokemon Checkup such as from Poison or Burn would not count.
Source: Obsidian Flames FAQ; TPCi Rules Team (2023-08-10)
Do I include Brassius in the count of my hand?
No, by the time you are counting the cards in your hand Brassius is already in play; it is no longer in your hand.
Source: Obsidian Flames FAQ; TPCi Rules Team (2023-08-10)
If Pokemon League Headquarters is in play and I have Lunatone with the "New Moon" Ability and also Solrock in play, do my Basic Pokemon have an extra {C} cost to their Attacks?
No, but your opponent's Pokemon do.
Source: Obsidian Flames FAQ; TPCi Rules Team (2023-08-10)
What happens if I play Worker and cannot draw any cards? Do I still get to discard a Stadium or not?
Yes, they are two separate sentences so you do as much of it as you can.
Source: TPCi Rules Team (2023-07-13)
Say Gapejaw Bog stadium and Ting-Lu ex with "Cursed Land" Ability are both in play. If I put Lumineon V onto the Bench, can I use its "Luminous Sign" Ability or will it be blocked because it has damage counters on it?
Since Luminous Sign and Gapejaw Bog are simultaneous effects, it is up to the player to choose the order in which they will be applied.
Source: TPCi Rules Team (2023-07-13)