Marth killer
The Marth killer is an advanced technique in Super Smash Bros. Melee used when edgeguarding certain characters with linear recoveries, most notably Marth (hence its name). It is performed by lightshielding and angling the shield away from the stage. Upon the shield being hit by the recovering character's up special, the shielder may slide off the stage and instantly grab the edge before the recovering character can, resulting in an instant edgehog.
The reason the Marth killer works is that you can ASDI during shieldstun[1]. Therefore, contrarily to popular belief, it doesn't matter which part of your shield Marth's sword hits, you will perform a Marth killer nonetheless.
The common counter-strategy to a Marth killer is for the victim to recover higher than the ledge instead of aiming for the sweetspot. And while it is easy to punish Marth, or the other potential victims of this technique during their landing lag after their upB, it is generally a bad idea to let them touch the ground, since this gives them back their double jumps, and in Marth's case, it gives his side B (Dancing Blade) the ability to air stall again. They could also potentially ASDI down which reduces your odds of getting a KO. So while doing a Marth killer every time does guarantee you a free hit, this would still be less rewarding than choosing a riskier option that would actually result in Marth's death, such as a shine spike.
Here is a list of the characters against whom you can perform a Marth killer.
- Link (Spin Attack)
- Peach (Peach Parasol)
- Marth (Dolphin Slash)
- Roy (Blazer)
- Young Link (Spin Attack)
In Project M
In Project M, until version 3.5, doing a Marth killer was impossible due to the lack of shield ASDI, which is what makes this technique work. It is now possible to perform a Marth Killer in Project M, but the lack of lightshields changes a few things about this technique. Firstly, depending on the size of your character and the size of its shield, you might have to angle your shield diagonally down instead of simply angling it away from the stage. If you don't, Marth will be able to sweetspot the ledge without hitting your shield. However, since you cannot grab the ledge if you are holding down on the control stick, you have to release your control stick after Marth hits your shield. Secondly, shield stabbing wasn't a factor when doing a Marth killer in Melee, but in Project M it is highly likely that if your shield's health is low, you will not be able to perform a Marth killer.