Stage spike

A stage spike refers to when a character is knocked against part of the stage and falls downwards in a similar fashion to a meteor smash. Stage spikes can be used as an edgeguarding or guard break technique, depending on who is doing the stage spiking. At the current moment stage spikes cannot be meteor canceled unlike meteor smashes, due to the game not recognizing it as a meteor smash. Due to the hitstun from being stage spiked, the victim will most likely not be able to recover, but if they possess supreme technical skill they may be able to wall tech to cancel momentum and recover. A stage spike can also be performed by using some moves on opponents who try to edgehog.

Applications
Stage spikes are useful for characters who do not have meteor smashes. However, they are great for all characters when the situation arises. Characters such as and, whose down aerials are not meteor smashes and instead produce mostly horizontal or vertical knockback, can stage spike recovering opponents using those moves given the right opportunity. Players looking to stage spike must be careful, though, as over-extending off the stage can often lead to an SD of their own.

Self-stage spiking
In the main Smash Bros games, self-stage spiking involved a failed recovery move. Self-stage spiking occurs when a player tries to recover, but instead, in addition to missing the Ledge, ends up hitting part of the stage, bouncing off into a helpless state. Ness is particularly self stage-spike vulnerable as his PK Thunder can launch him right at the edge of a wall. However, in Super Smash Flash 2 stages have become more recover friendly so it's not possible or unlikely to self-stage spike, but they can still can get stuck under certain stages.