Active Player

Active Player is the player currently taking his or her turn.

Details
During your turn, you become the active player. If its your opponents turn, you are the non-active player.

When the ability of multiple cards trigger at the same time, they resolve in progress, starting with the active player.

In the official Q&A on the Duel Masters Official Homepage, it was referred to as "that turns player", and the non-active player as "the other player. "Turn player" and "non-Turn player" were later seen.
 * In the Duel Masters General Game Rules released in July 2015, it is written as "turn player" and "non turn player".
 * Some results of battle can differ depending on the active player, such as the results of a battle between Death March, Reaper Puppeteer and Glenmalt, Dragon Edge.