To avoid the danger of opportunity attacks during a tactical retreat, a fighter can choose to disengage from combat. This action requires the fighter's full attention and agility, using up an attack action to withdraw safely.
By choosing to disengage, the character eliminates the possibility for their opponents to execute an opportunity attack due to their departure, making him out of range of the opponent's weapon.
This tactical maneuver allows the fighter to reposition themselves on the battlefield safely, ready to continue the fight or support their allies from a new strategic location.