Player 1 has pair of jacks and goes all in...$2000. player 2 has pair of kings and goes all in...$500. player 3 has pair of queens and goes all in...$2000. So what does each player win?
You imply that none of the players improve on the board, so we'll work with that assumption, and I will also assume that no additional money from other players is in the pot.
Player 1 has J♠J♣ and $2000
Player 2 has K♠K♣ and $500
Player 3 has Q♠Q♣ and $2000
Everyone goes all-in before the flop. Because player 2 has less than the other players, a main pot will be formed that has $500 from each player. So, this main pot will contain $1500. This is the only portion of the pot that player 2 is eligible to win, because he can win no more than he risks from each of the other players.
A side pot is then created between players 1 and 3. $500 has already been removed from each to satisfy the main pot, so there's a side pot which contains $1500 from each player here, so $3000 total.
To summarize here:
- The main pot contains $1500. All players can win this.
- The side pot contains $3000. Players 1 and 3 can win this.
At the end of the hand, the two players involved in the side pot reveal their hands. Queens beat jacks, so player 3 wins the side pot and player 1 is eliminated from further consideration. Then the main pot is decided between the remaining two players. The kings beat the queens, so player 2 wins the main pot.
- Player 1 loses his $2000.
- Player 2 wins a pot of $1500 for a net gain of $1000.
- Player 3 wins a pot of $3000 for a net gain of $1000.