The Formation Change Gate (フォーメーションチェンジゲート,Fōmēshonchenjigēto?) is a mechanic that appeared in Sonic Heroes. When a team passes though a formation change gate, it automatically causes the team to change into either Speed formation, Power formation or Flight formation, depending on the gate's type.
The Formation Change Gates appear to be floating photosensors that gives off three sets of beams of light. These lights are in three different colors, each corresponding to the character type in the game: red for the Power Type, yellow for the Fly Type and blue for the Speed Type.
Formation change gates are located in various stages throughout Sonic Heroes. When a team (Team Sonic, Team Rose, Team Dark or Team Chaotix) goes through a formation change gate, it will automatically change the team's formation type to the specific formation type that it has (i.e. if Knuckles the Echidna, the Power Type of Team Sonic, was in the lead of Team Sonic, and went through a Speed formation change gate, he would be switched out with Sonic the Hedgehog, Team Sonic's Speed Type).
The formation change gates mainly serve to automatically switch the chosen team's formation type to the one most suited for the upcoming section of the game's stage that the player has to pass through. However, there are certain occasions where three formation change gates are lined up together, giving the player a choice of the specific formation.