Light Speed Dash

The Light Speed Dash (ライトスピードダッシュ), also simply known just as the Light Dash, is an ability that can be performed by Sonic and Shadow in certain games of the Sonic the Hedgehog series. It allows them to Spin Dash along trails of rings at light speed, even in mid-air, which can allow access to new areas. It first appeared in Sonic Adventure.

Sonic Adventure
In Sonic Adventure, the Light Speed Dash can be obtained when Sonic collects the Light Speed Shoes. To activate the move in this game, Sonic must charge up his Spin Dash until he says "Ready!" (this will end the spinning and allow Sonic to walk around as long as the action button is held). He can then approach a trail of rings and release the action button to travel along the path of the rings.

The Crystal Ring is an optional upgrade that halves the charging time needed to perform the Light Speed Dash.

The Ancient Light allows Sonic to perform the stronger move, the Light Speed Attack, which is performed the same way but now has the ability to damage multiple enemies.

Sonic Adventure 2
In Sonic Adventure 2, the Light Speed Dash is available to both Sonic (in the Hero story) and Shadow (in the Dark story). Sonic accesses the move when he, again, collects the Light Speed Shoes. Shadow must collect the Air Shoes to perform the same move.

Unlike in Sonic Adventure, Sonic only has to approach a trail of rings and press the action button as opposed to charging. Curiously, from this game and onward, the Light Dash is capable of damaging foes in the middle of a ring path and not just items. Sonic also no longer Spin Dashes and just simply dashes along the trail.

Both characters can upgrade to the Light Speed Attack by collecting the Ancient Light.

Sonic Heroes and Shadow the Hedgehog
In Sonic Heroes and Shadow the Hedgehog, both Sonic and Shadow have access to the Light Speed Dash from the beginning of the game. In Shadow the Hedgehog, any rings that are accidentally collected prior to the Dash turn clear, and can still be dashed across. Additionally, in said game, the second action button (X on Gamecube) is used, instead of the first (B on Gamecube).

Sonic the Hedgehog (2006)
In Sonic the Hedgehog, both Sonic and Shadow can gain the ability to perform the Light Speed Dash by collecting the Light Chip (Sonic) and Air Chip (Shadow). The move is required to reach the first stage as Sonic.

Sonic Unleashed
In the PlayStation 3 and Xbox 360 versions of Sonic Unleashed, Sonic once again accesses the Light Speed Dash by collecting the Light Speed Shoes. In the PlayStation 2 and Wii versions of the game, he has access to the move from the beginning of the game.

Sonic Colors
The Light Speed Dash once again appears in Sonic Colors. However, it is only useable while under the effects of the green Wisp.

Sonic Generations
The Light Speed Dash returns in Sonic Generations as one of Modern Sonic's normal abilities; however, it can only be performed near certain ring paths, which are surrounded by a clearly discernible ripple effect. Also, the button required to perform the move is shown.

Sonic X
In the Sonic X continuation, the Tornado X can release rings into a line called the Ring Tunnel, which Sonic then spin dashes through the tunnel. However, since there is only one other ring, one that lets Sonic Spin Dash, and does not get collected, Sonic does not collect the rings in the Ring Tunnel.

Trivia

 * Out of all the characters in the videogame continuity, only Sonic and Shadow have been capable of performing this move.
 * In Sonic Heroes, Team Sonic and Team Dark could perform the move because of Sonic and Shadow, but Team Rose and Team Chaotix could not perform the move because Amy and Espio were incapable of using it.
 * Sonic can actually injure a Chao in Sonic Adventure DX by using the Lightspeed Dash. To pull it off, the player must charge the move (and keep it charged), then walk to a Chao and pick it up (this is possible on the GameCube version by holding the B Button to charge, then walk to a Chao and press X to pick it up). Then, when the player puts the Chao down, Sonic will immediately fly forward, sending the Chao flying.
 * In Sonic the Hedgehog (2006), it is considerably harder to execute the move, due to the Stomp move being mapped to the same button as the Lightspeed Dash (X on the Xbox 360, Square on the PlayStation 3). If players are not careful, they could end up stomping to their death rather than flying to safety.
 * In the 360 and PS3 versions of Sonic Unleashed, the Lightspeed Dash is the last move to be unlocked. This is oddly different, due to every other game before it either offering the move as the first to be unlocked or automatically unlocked.