Dash attack canceled up smash
The dash attack canceled up smash (abbreviated to DACUS, also referred to as Boost Smashing) is an advanced technique in Super Smash Bros. Brawl which allows a character to cancel their dash attack with an up smash, while retaining the momentum from the dash attack. It is similar to techniques such as a slide smash, a running up smash or a jump-canceled up smash, but a DACUS is executed differently and with some characters, it has the potential to cover much more distance than their other approaching up smash options.
DACUS was briefly possible in Super Smash Bros. for Nintendo 3DS, although it was removed in patch 1.0.4 and it was never possible in the Wii U version, although Shulk is able to perform a similar technique named MonaDACUS by using the momentum of a canceled Speed Monado Art to boost himself forward.
Performing the technique
As its name implies, a dash attack canceled up smash is performed by inputting a dash attack and then quickly inputting an up smash. There are multiple ways to perform a DACUS but the simplest way is to input a dash attack with the C-Stick (or D-Pad if the player is using the Nunchuk) and then inputting an up smash with a normal control stick. Pressing down on the C-stick/D-pad is the best way to start a DACUS (assuming the C-stick/D-pad is set to smash attacks) as if the player hits forward during the beginning of the dash, they will perform a forward smash instead. This makes hitting down rather than forward both easier and more optimal. The up smash must be performed on at least frame 3 of the dash attack's animation although most characters can perform it slightly later than frame 3. The up smash can be buffered on the previous frame however. The up smash can alternatively be replaced with a grab to perform a Boost grab.
Any character can perform a DACUS, but only certain characters can take advantage of it, as the distance a DACUS travels depends on the character. Each character has a different window where they can DACUS. For example, Snake has a very large DACUS window from frames 3-8, making his easier to perform than a character like Sheik who has a short DACUS window on only frame 3. The exact frame a character initiates a DACUS can also affect how much distance it gains. For example, Falco can DACUS from frame 3-5 of his dash attack but he gains less distance the later he inputs his up smash. Link can DACUS from frame 3-6 of his dash attack but he gains the most distance when he inputs his up smash on frame 5.
If a character increases in size (with a Super Mushroom or a Lightning Bolt), their DACUS window will be extended, making it easier for them to perform a DACUS. The opposite applies if the character decreases in size.
Dash attack canceled up smash windows
The uses a DACUS has are largely identical to that of a slide smash, a running up smash or a jump-canceled up smash although its potential greater distance makes it more applicable in more situations. It is mainly used as a punishment or an approach option, particularly from far distances. The great amount of distance it can cover with some characters makes it an excellent whiff punishment option or as an option to punish landings, especially since the player can charge the up smash to make it stronger and cover more distance.
A DACUS can also be used as a followup in some scenarios. An example of this is that if Sheik aerial grab releases her opponent, she can then followup with a DACUS to hit or even potentially KO the opponent. As another example, Falco can use his DACUS as a followup in multiple situations including after a landing laser, after a laser lock or after a down throw.
Some characters cover less distance with a DACUS than a running up smash although this does actually have a use with some characters. Captain Falcon's and Charizard's running up smashes for example cover a lot of distance and it can often result in their up smashes either whiffing completely or they land the first hit but the opponent falls out before the second hit can connect. When they DACUS however, they cover much less distance, which can allow them to more reliably connect their up smash at close distances.
The Gatling Combo involves using a DACUS, but the dash attack is cancelled after the hitbox comes out, meaning that both the dash attack and the up smash have the potential to hit. The Gatling Combo is performed by inputting a dash attack and then performing an up smash while the opponent is in hitlag, which makes it easier to perform than a regular DACUS. It functions in a very similar way to the jab grab technique in Smash 64, except the player is performing a dash attack into an up smash, rather than a jab into grab. The technique only works with characters who have a dash attack which comes out at least two frames before their DACUS window ends. Falco, Snake, and Wario are the only characters who can perform the Gatling Combo; as their dash attacks are fast enough and they have a long enough DACUS window to perform it.
The combo is usually used to rack up some early percent damage or to pressure shielding opponents. Its overall utility varies between the three characters who can perform it. Wario's is the least useful as his only works at very low percents and even then, his opponent can easily fall out of or escape his up smash, especially floatier characters. Falco's works for a longer period of time than Wario's and his up smash is far more rewarding overall. Snake's slides too far for both the dash attack and the up smash to reliably hit (even when he dash attacks into the ledge) although Snake's extremely long slide distance makes it an excellent cross-up and approach tool, especially since it covers more distance than his dash attack on its own.
More characters gain access to the Gatling Combo if they increase in size due to their extended DACUS windows and likewise, the few characters who can perform the Gatling Combo will lose the ability to do so if they shrink although this has no effect in competitive play.
Characters with a sliding DACUS
Buffered dash attack canceled up smash
The buffered dash attack canceled up smash (shortened to BDACUS) is another variant of DACUS. A BDACUS basically involves buffering a dash attack out of another action (during the 10 frame buffer window) and then cancelling the dash attack with an up smash. This allows the player to cancel the dash attack during its first or second frame which is normally not possible. In order to perform a buffered dash attack, the player has to quickly tap the stick forward, let go and then press attack, all within the 10 frame buffer window. In order to do a BDACUS, the player then has to input an up smash during the buffered dash attack. The easiest way to perform a BDACUS is to quickly tap the stick forward, let go and then tap the C-stick up twice (if the C stick is set to smash attacks). This works because when an up smash is buffered out of a buffered dash input, the game will strangely buffer a dash attack instead.
When the dash attack is cancelled on the first possible frame (which can be buffered by buffering the up smash after the dash attack), it has a similar effect to a running up smash. This is naturally useful as a punishment option, especially for characters with long running up smashes but this is not what is referred to as a BDACUS.
A perfect BDACUS occurs when the dash attack is cancelled on the second frame. This is very difficult to achieve due to its frame perfect nature. Inputting up smash too early will result in the aforementioned instant running up smash and inputting the up smash too late will either lead to a regular DACUS or a standard dash attack depending on the timing. The distance a perfect BDACUS covers can vary from a regular DACUS. For most characters, it either covers less distance or a similar distance compared to a normal DACUS, although there are a few characters who gain more distance from a perfect BDACUS.
For the most part, the only characters who gain any significant millage out of a BDACUS are characters who already have a strong DACUS. A BDACUS is particularly useful for Falco and Jigglypuff since their perfect BDACUS covers more distance than their regular DACUS. Even for characters who get less out of a perfect BDACUS (such as Wolf), they can still buffer a dash attack and wait for the appropriate window to do their DACUS. The only character who solely benefits from BDACUS over a regular DACUS is Diddy Kong. Diddy Kong's regular DACUS covers less distance than his running up smash but his BDACUS covers much more distance, covering more than half of Final Destination.
BDACUS was never possible in any version of Super Smash Bros. 4 due to the altered buffer system removing the ability to perform buffered dash attacks.
Prior to patch 1.0.4, DACUS was still possible in Super Smash Bros. for Nintendo 3DS, with Sheik, Wario, Donkey Kong, Villager, Robin, Greninja and Rosalina & Luma notably benefitting from the technique. As of version 1.0.4, however, no characters can DACUS at all and the technique was never possible in Super Smash Bros. for Wii U. In Super Smash Bros. Ultimate, the DACUS continues to remain absent from the game, which notably hinders Snake, as his DACUS is a vital part of his metagame in Brawl.