Multiplayer

This is my edited version of Wizards of the Coast's Pokémon Multiplayer Rules V 1.3 Beta , rewritten for clarity, tweaked for more casual use case, and updated with modern terminology. I also included some official rulings from the time - those relevant to the cards I own.

TL;DR

• Based on the results of a coin flip, a player from the starting team takes the first turn, followed by both players on the opposing team one after the other, the round concluding with their teammate; rinse and repeat in clockwise order.
• Each player sets up three prizes. When a prize is earned, one of the earning team members takes a prize. If they run out, their teammate takes a prize instead. The game continues until one team has drawn all 6 of its collective prize cards or both players on a team are eliminated.
• A player is eliminated if their last Pokémon in play is Knocked out or if they deck themselves out.
• During their turn, the player decides which player on the opposing team they will be attacking. Only that target player's Pokémon may take damage from an attack.
• Trainers, Pokémon Powers, and effects specify the affected target. Depending on the text on the card, the target may be the invoking player themselves, their teammate, both teammates, a player on the opposing team, both players on the opposing team, or everyone. The costs specified by those cards, however, are always applied to the invoking player.
• Players may not attach any of their cards to their teammate's Pokémon but may transfer counters, markers, or effects between them e.g. using Pokémon Powers.
• Only 1 Stadium card may be in play at a time and it affects all players in the game.
• Special Conditions and effects trigger between turns or at the end of each turn (meaning four times per round).

Setup

1. Each 2-player team designates one team member as Player A and the other as Player B.
2. Everybody sits around a single table, with team partners sitting adjacent to each other. Player A from each team sits opposite Player A from the opposing team.
3. Player B from one team flips a coin, and player B from the other team calls out the desired result. The team that won the coin flip gets to decide which team starts first. After setup, player A from the starting team goes first and the play continues in clockwise direction.
   • For example: player B from team 2 (2B) calls heads. Player B from team 1 (1B) flips a coin and flips tails. That means player A from team 1 (1A) will go first. Starting order will therefore be: 1A, 2B, 2A, 1B.
4. Players shuffle their decks and draw 7 cards each and look at their hand. Player A from the starting team determines if they must declare a mulligan or not. If they do, each member of the opposing team may draw up 1 card. Each following player then does the same. Mulligan order is the same as the play order.
5. Player A and player B on each team each sets up 3 prize cards (for a total of 6 per team).

Rules

Attacking

When it's your turn, your Pokémon can Attack either of the opponent's Pokémon. When you're ready to Attack, you choose the opponent you'll be targeting. The targeted player's Active Pokémon becomes the Defending Pokémon.

Targeting

Most Trainers, Pokémon Powers, and effects specify the affected target.

• "You" = can be played on either you or your partner.
• "Your opponent" = can be played on either member of the opposite team.
• "Defending Pokémon" = can only be played on the targeted player's Active Pokémon.
• "All Pokémon" or "all Benched Pokémon" = affect all 4 players' stated Pokémon

Whether or not Trainers, Pokémon Powers, and effects may target you or your partner depends on the wording on the card.

• If you play Pokémon Trader, you can choose to play this card on yourself or on your teammate on your turn. Your teammate must have a Pokémon in their hand in order for you to play it on them, however.
• If you play Pokémon Breeder, while it may appear that you could play this card on your teammate, that is not the case as other players are not allowed to evolve their Pokémon during your turn.
• If you play Bill, since there is no "you" or "your" in this card's text, you cannot play this card on a teammate, only on yourself.

In cases where a player gets to choose something of their opponent's, they choose which opposing team member gets affected.

• If you play Gust of Wind, you choose which player of the opposing team will be affected (and later which Pokémon).
• If you play Double Gust, you choose which player of the opposing team will be affected (and later which Pokémon) to resolve Trainer's first condition. However, the affected opponent then chooses which player on your team team will be affected (and later which Pokémon) to resolve Trainer's second condition.

Only the owner of a Pokémon, Trainer card, or effect can choose whether to use that effect or allow their teammate to do so. You cannot use any of your teammate's Pokémon Powers, Attacks, or effects on your turn.

Cards and effects that refer to both players only affect the chosen players on each team. Cards that affect all players, affect every player in the game.

• Muk's Pokémon Power (Toxic Gas) disables all other Pokémon Powers, on your and your opponents' team.

Whenever you put into play any continual Pokémon Power that specifies "your opponent", you must immediately designate which opponent it is targeting.

• If you put Neo Genesis Slowking into play, you must immediately designate which player on the opposing team its Pokémon Power is targeting.
• If you put Jungle Dodrio into play, you must immediately designate which player on your team its Pokémon Power is targeting.

Whenever you put into play any continual Pokémon Power that specifies "your Pokémon" you must immediately designate whether it is targeting your Pokémon or your teammate's Pokémon. Once an effect has its target designated, that target cannot change while that Pokémon remains in play. If you have a Pokémon Power targeting one opponent, if that opponent leaves the game that Pokémon Power cannot be retargeted unless the Pokémon with said Pokémon Power leaves play.

Once you designate which player is "you" or your "opponent", every instance of "you" or "opponent" in that effect refers to that same player, except costs.

Many Trainers, Pokémon Powers, and Attacks have costs associated with playing or using an effect. These costs are always applied to the person playing the card (not necessarily the one using the effect of the card). This means that you cannot split the effects of a card between both players on a team (yours or your opponents').

• If you play Professor Elm, as you are the person who is actually playing the card (taking it from your hand and discarding it) you cannot play any more Trainer cards that turn.
• If you play Pokémon Breeder Fields, you must either choose 1 or 2 of your Pokémon, or 1 or 2 of your teammate's Pokémon. You cannot choose 1 of each.

Stadiums

Stadium cards affect all players in a game. Only 1 Stadium card may be in play at a time (standard rules apply).

Prizes

When a player earns a prize card by Knocking out one of the opposing Pokémon they can choose to draw one of their Prize cards or have their teammate draw one of their Prize cards. If one player has already drawn their last prize card, the next time they earn the right to draw another Prize card their teammate must draw one of their Prize cards instead. If a triggered Pokémon Power, Attack, or Special Condition knocks out a player's own Pokémon, the players on the opposing team may discuss which of them gets to draw a Prize card with player A having the final decision.

Eliminations

If a player has their last Pokémon in play Knocked out or has decked themselves out, they are eliminated from the game. All of their cards (including Stadiums) are removed from the game. Their teammate must add to their prize cards a number of cards from the bottom of their deck equal to the number of remaining prizes the eliminated teammate had left. Play continues as before (each remaining player taking turns in a clockwise manner) until both players on one team are eliminated.

• In the event that the remaining team player does not have enough cards in their deck to place out these prize cards, that player is considered to have decked themselves out and is eliminated from the game.

Victory Conditions

The game continues until one team has drawn all 6 of its prize cards or both players on a team are eliminated (having their last in play Pokémon Knocked out or having decked themselves out).

Transference

You cannot attach any of your cards to any of your teammate's Pokémon. You also cannot draw, trade, or transfer any cards between you or your teammate's cards, decks, or Pokémon. You can trade counters, markers, or effects between teammate's Pokémon when applicable.

• Focus Band can only be attached to one of your Pokémon, not your teammate's.
• Alakazam's Damage Swap Pokémon Power allows you to either move a damage counter from one of your Pokémon to another of your Pokémon or move a damage counter from one of your teammate's Pokémon to another of their Pokémon. You cannot use this power to move a counter from one of their Pokémon to one of yours (or vice versa).

Checkups

Special Conditions and effects that trigger at the end of each turn, trigger at the end of each player's turn (like Poison, Burn, or Sleep). Special Conditions that trigger or end at the end of your turn still wait until the end of your particular turn (such as Paralysis).

Official Rulings

We cannot attack our partner in Team Battle - I had somebody try that at Worlds while I was judging team. They didn't want to flip to use an Eeeeeeek attack so they aimed at their partner.Correct, you cannot attack your teammate. (Jun 12, 2003 WotC Chat, Q1902)

In Team Play, if a player does something that causes his partner to discard a non-Colorless energy card (say, Pokemon Center) with Ecogym in play, would those non-Colorless energies return to the player's hand?Yes, they would get the energy back. We're ruling that it will work for now... (Jul 18, 2002 WotC Chat, Q21)

In Team Play, when using Feint Attack against a team with one baby and one non-baby active, can you *attack* the non-baby Pokemon but use the attack's effect against the other opponent's (the one with the baby) Pokemon due to the "your opponent's" clause?Yes. (Aug 1, 2002 WotC Chat, Q255)

During my turn, can I have my Cleffa "Eeeeeeek!" and tell my teammate to shuffle their hand & draw 7 cards?Yes you can! (May 23, 2002 WotC Chat, Q331)

Pichu's Zzzap - in Team Play, does the attack affect all four players in the game, or do you simply pick one player from each team?All four. (Mar 21, 2002 WotC Chat, Q107)