A Vespiquen that used its "Mach Wind" attack on my previous turn was hit by Grimer's "Sticky Liquid" attack during my opponent's turn. In this instance, what is Vespiquen's retreat cost during my next turn?
It has no Retreat Cost. When effects that increase something like Retreat Cost by a particular amount are stacked on top of effects that make something like Retreat Cost vanish, the vanishing effect takes priority.
Source: Undaunted FAQ (2010-09-09), PUI Rules Team (2010-09-09)
When using Misdreavus' "Dual Draw" attack, do the players have to draw all 3 cards, or can they just draw 1 or 2 (or none)?
You must draw all three if you are able to (or as many as you can if you have less than three). The attack does not say "up to 3 cards".
Source: Undaunted FAQ (2010-09-09), PUI Rules Team (2010-09-09)
When I use Smeargle's "Portrait" Poke-POWER to look at my opponent's hand, can I terminate the power's effect without choosing a Supporter card?
No, you cannot. You must choose a Supporter card when you use the effect if the opponent has one in their hand.
Source: Undaunted FAQ (2010-09-09), PUI Rules Team (2010-09-09)
Can I use Smeargle's "Portrait" Poke-POWER if I have already used a Supporter this turn?
Yes, you are not playing a second Supporter, you are just using the Supporter's effect as the effect of the power.
Source: Undaunted FAQ (2010-09-09), PUI Rules Team (2010-09-09)
When using Slowking's "Opponent's Choice" Poke-POWER, do you have to show your opponent what the cards are since it says 'you may reveal the top 2 cards'?
Of course you have to show the opponent what the cards are. The "you may" refers to using the power, not to being able to use it without showing them the cards.
Source: Undaunted FAQ (2010-09-09), PUI Rules Team (2010-09-09)
When I switch a Prize card and a card from my Deck with Rotom's "Mischievous Trick" Poke-POWER, can I look at either card?
No, you cannot. Keep both cards face-down when you switch them.
Source: Undaunted FAQ (2010-09-09), PUI Rules Team (2010-09-09)
Can I use Rotom's "Mischievous Trick" Poke-POWER when I have no cards in my deck, to put a Prize card into my deck?
No, you can't. That would be far too mischievous.
Source: Undaunted FAQ (2010-09-09), PUI Rules Team (2010-09-09)
Can I still play Supporters or Stadiums while Vileplume's "Allergy Flower" Poke-BODY is in effect?
Yes. They are not Trainers.
Source: Undaunted FAQ (2010-09-09), PUI Rules Team (2010-09-09)
If I attach Memory Berry to Mareep, evolve it to Ampharos, then attack with "Static Electricity", would I search my deck for energies based on the number of Mareep or the number of Ampharos in play?
In the latter part of the Static Electricity attack Where the English card says "attach them to Mareep", the Japanese card actually says "attach them to this Pokemon". So, you would count the number of Mareep in play and attach that many Lightning energy to Ampharos.
Source: PUI Rules Team (2010-07-15)
Can I play "Pokemon Circulator" if my opponent doesn't have any benched Pokemon?
Since Pokemon Circulator requires your opponent to switch with a benched Pokemon, you can't play it unless your opponent has a Pokemon on the bench.
Source: Unleashed FAQ (2010-05-13), PUI Rules Team (2010-05-13)