Performing the attack sends Fox darting forwards with incredible speed, which causes an afterimage effect and hurts any enemies in his path. It deals little damage (3%) and has very little knockback; however, if a foe gets hit with it at over 295% (such used in Sudden Death), he/she will be instantly launched upwards and get inevitably KO'd. In Melee, the dash is so fast that if used facing an edge at the end of a stage, the attack will cause Fox to dart over the ledge, resulting in going into the helpless state, and usually causing a self-destruct. This was removed in Brawl. In Super Smash Bros. 4, the move can no longer go over a grabbable ledge, and no longer puts Fox in a helpless state, and in Super Smash Bros Ultimate, the move loses the ability to pass through shields. However, its knockback for its grounded variant has been drastically increased, KOing middleweights at around 180% or earlier with rage.
The move may also be used by players as a useful recovery technique, since the move can quickly cover about half of the length of Final Destination and makes up for a faster option than Fire Fox. However, compared to Fire Fox, Fox Illusion only has 1 angle of travel and gives less momentum and maneuverability after the dash despite technically covering more distance.
Because of the speed Fox travels during the move, he is capable of skipping through attacks with slow-moving and/or small hitboxes, resulting in the impression that the move gives him invincibility or intangibility.
Fox Illusion, along with Falco Phantasm and Wolf Flash, can be shortened by pressing the special button while or right before Fox is moving. The length to which the move shortens depends on the timing of the button press. Specifically, for Fox, there are five shortening lengths, 1 for each of the 5 frames he is traveling. Since shortened side-special moves require opponents to time their attacks differently in order to edgeguard Fox, these variants can be used as highly effective mix-ups for recovering. Fox can no longer do this in Super Smash Bros. 4.
Special Move customization was added in Super Smash Bros. 4. These are the variations:
Fox Illusion is an exclusive move to the Super Smash Bros. series, but it may have been inspired by the Arwing's ability to fly at lightspeed after traveling through warps in Meteo and Sector X in Star Fox 64.