If Ariados' "Leech Life" attack does 30 damage but the opponent's Active Pokemon has only 10 HP remaining, how many damage counters will be removed from Ariados?
Leech Life does 30 damage, which is not affected by the fact that the KO only required 10 damage. Therefore, Ariados will remove 3 damage counters, or all if there are less than 3.
Source: HeartGold & SoulSilver FAQ (2010-02-11), PUI Rules Team (2010-02-11)
Can I use Mantine's "Group Swim" attack to put one half of a Lugia LEGEND card in my hand?
Yes. Either half of the Lugia LEGEND card is still considered "a Water-type Pokemon", so you can search for it with Group Swim.
Source: HeartGold & SoulSilver FAQ (2010-02-11), PUI Rules Team (2010-02-11)
When I use Typhlosion's "Flare Destroy" attack, which player chooses the Energy card to discard from the Defending Pokemon?
The player that used the attack gets to choose which Energy cards get discarded from both the Active and Defending Pokemon.
Source: HeartGold & SoulSilver FAQ (2010-02-11), PUI Rules Team (2010-02-11)
If the Defending Pokemon doesn't have any Energy cards attached to it, does Typhlosion's "Flare Destroy" attack still require Typhlosion to discard an Energy from itself?
Yes, if the attacking Pokemon has any Energy cards attached, it must discard one of them.
Source: HeartGold & SoulSilver FAQ (2010-02-11), PUI Rules Team (2010-02-11)
If my opponent has less than 3 cards in his or her deck, so that I can't reorder the top 3 cards, can I still use Slowking's "Second Sight" Poke-POWER to look at the remaining cards in the deck?
Yes, you look at your opponent's remaining cards, then put them back in the deck in any order.
Source: HeartGold & SoulSilver FAQ (2010-02-11), PUI Rules Team (2010-02-11)
Can I use Ninetales' "Roast Reveal" Poke-POWER when I have no cards in my deck?
Yes, you do as much of the power as you are able; discard 1 Fire Energy card from your hand, then the Poke-POWER's effect ends, without drawing any cards.
Source: HeartGold & SoulSilver FAQ (2010-02-11), PUI Rules Team (2010-02-11)
Can Typhlosion's "Afterburner" Poke-POWER be used if there is no Energy in the discard pile, just to place a damage counter on one of my Pokemon?
No. Since you can't attach an Energy from your discard pile to one of your Pokemon, you can't use the rest of the power.
Source: HeartGold & SoulSilver FAQ (2010-02-11), PUI Rules Team (2010-02-11)
If I use Pokemon Communication to put a Pokemon into my deck, am I allowed to voluntarily fail and choose to take no Pokemon out of my deck?
The contents of your deck is not public knowledge so the deck search can fail, even if you've just put a Pokemon into the deck.
Source: PUI Rules Team (2010-02-04)
If my opponent uses Pichu's "Playground" attack on the first turn of the game, and I am going second, can I evolve the Pokemon I put onto my Bench with "Playground" since I did not put them in play on my turn?
It is a basic game rule that neither player can normally evolve any Pokemon on their first turn of the game, even if they are going second.
Source: PUI Rules Team (2010-02-04)
May I use Ambipom [G]'s "Tail Code" attack if my opponent only has an Active Pokemon and no Benched Pokemon?
Yes you can, although it won't move or discard the energy. There must be a Pokemon on the bench or you can't move the energy off the defending Pokemon.
Source: PUI Rules Team (2010-01-28)