Reboot Phase (リブートフェイズ Ribūto Feizu) is the first phase of a turn. During this phase, the turn player switch all of their cards in Square and Resource from Sleep into Reboot. It is followed by Draw Phase.
Certain automatic abilities and effects that has the timing of "at the beginning of the Reboot Phase" take place in this phase. If it is the first turn of the game, ability with the timing of "at the beginning of the game" also activates as well.