All matches in Pokkén Tournament begin in Field Phase. During this phase, fighters are free to move in three dimensions (forwards and backwards, sideways, and jump). With a greater range of movement, fighters get to use Ranged Attacks by pressing the Y button. Additionally, fighters can perform homing attacks by pressing the X button. All of these moves can be performed in tandem with the jump and directional buttons as well.
The fighters' goal in Field Phase is to safely whittle down their opponent's HP and evade attacks, due to the limited possible moves that can be performed in this phase are mediocre in damage output, and greater range of movement. Noticeably, it is much easier to shift to Duel Phase than the other way around.
Landing certain attacks in this phase causes a Phase Shift, with one fighter recovering some HP while the other loses some of their recoverable HP.