Blue Shell

The Blue Shell (officially referred to as a Spiny Shell) item flies forward and attacks the racer in first place.

Use

When the Blue Shell is thrown by a player, it has multiple "phases" it will go through.

First, the Blue Shell travels along the ground along the center of the road. Any racers hit by the the blue shell will be damaged and flip over, unless they have invincibility. Course hazards like train cars will be lifted into the air as the blue shell approaches, to avoid getting hit or blocking it.

Once the blue shell gets close enough to the player in first place (the exact distance is unknown), it will "lock on" to the racer in first place, raising into the air and flying directly toward them. It will no longer follow the path of the road and will ignore obstacles. At this point, the blue shell has already chosen its target, so even if a new racer takes first place, they won't get hit.

Finally, the blue shell will reach its target. At this point, the blue shell circles around the player twice, winds up, then dives toward its target. It explodes, creating a large blast that will damage anyone within the blast radius.
The targeted player will do a flip and be stunned for ?? seconds. Any other players who get hit will only spin out, allowing them to maintian some of their forward momentum, and will only be stunned for ?? seconds.

Dodging

The Blue Shell can be dodged or destroyed using one of the following methods:

• Activating a Super Horn
• Using a Mushroom Boost
• Being in an invincibility item
• Having invincibility frames
• Getting picked up by Lakitu

Super Horn

The Super Horn item was added to the game for the very purpose of countering a Blue Shell. A Super Horn can be activated at any time when the Blue Shell is within range, and it will be cracked and destroyed. This can be done by any player, regardless of if they are being targeted or not. They just have to be in range of it.

Mushroom Boost

You can use a mushroom boost from a Mushroom, Triple Mushroom, Golden Mushroom, Ground Mushroom, or even by using someone else's triple mushroom. When the Blue Shell goes in for the kill, it will rear back, showing its belly first. Then, it tilts forward, attacking you with the spikes on its back. This is the 12-frame window where you can activate a mushroom to dodge the blue shell.

Ways you can't dodge a blue shell

• Driving on a dash panel
• Getting a half-pipe boost
• With a Bomb

Contrary to popular belief, dodging a Blue Shell has nothing to do with speed. You're not actually outrunning the blue shell's explosion. Rather, the Blue Shell is specifically programmed not to damage you if you activate a mushroom at just the right time. This only applies to the person getting targeted by the Blue Shell, so you cannot dodge someone else's Blue Shell.