Instant charge-canceling

Instant charge-canceling is an advanced technique in Smash 4 exclusive to, , , and. These four characters, with a series of inputs, can almost immediately attack out of their chargeable special moves on the ground with their neutral attack, tilt attacks, or smash attacks without having to cancel them with their shield (or additionally in Cloud's case, by pressing the special move button again, which has an extra 8 frame delay).

How to perform
This is done by initiating the charge of Gyro, Limit Charge, Needle Storm, or Peanut Popgun, waiting a few frames, and at inputting the attack desired and immediately pressing the shield button afterwards. Cloud and R.O.B. are allowed to cancel the charge at any time and the attack inputted will come out immediately, while Diddy Kong and Sheik's instant charge cancel can only be done on the first frame of the charge; if done incorrectly, Diddy Kong will not cancel the charge at all, and Sheik will still go through Needle Storm's charge cancel animation before her attacks come out. Using Attack + Special Move to perform smash attacks makes it possible to use forward smashes out of the special move (as tapping the control stick or second stick for Smash Attack either left or right generates a roll), and tilting the control stick in the opposite direction can allow for reverse forward tilts or forward smashes. The grab button can also be used to instant charge-cancel, but unless the second stick is set to Smash Attack, the technique will require one-frame timing if it is to be used at all for the attack desired.

Applications
Due to special moves being able to be performed out of the running part of the dash, instant charge-canceling allows the three characters to approach with more options than just their dash attack, grab, or aerials, making it functionally similar to a run cancel in Melee. It also allows for extra offensive coverage while actually charging the special move. The only disadvantages to instant charge-canceling are its inability to be used when the move is fully charged, as well as its inability to be used in the air; Diddy Kong is the sole exception to these disadvantages, as he cannot store a charge with Peanut Popgun, and buffering the charge cancel makes the move behave differently in the air. Additionally, these special moves cannot be performed out of the initial dash (as none of them are side specials), so using instant charge-canceling for a different attack option out of the dash requires some prior distance traveled, though for all three characters, instant charge-canceling is faster than allowing the skidding animation of their dash to play out. Its somewhat complicated inputs could also lead to an input error and have another action (such as grab, shield, or a side special) occur instead of the attack desired, but with enough practice, this becomes a non-issue.

Instant Needle Storm cancel
(From 1:26-4:20)