Marth ranks 17th out of 41 on the official tier list, at the top of the B tier. This is a far drop from his top-tier placements in Melee and Brawl, where he ranked 3rd out of 26 and 5th out of 38, respectively.
Marth has been mostly reverted to his Melee iteration, with a few buffs, such as a slightly improved recovery and less lag on his down aerial. He retains his strengths from Melee, such as his disjointed range, fantastic spacing tools, and great edgeguarding capabilities. However, he still must contend with the same weaknesses, such as his poor horizontal recovery and lack of lingering hitboxes.
Unlike some other high-tier Melee characters, like Jigglypuff, Marth remains fairly viable in Project M, and is a strong pick for competitive play. Overall, though, Marth is less effective in the metagame due to the large amount of buffs other characters have received to counter the effectiveness of his tools. The tournament legal stagelist also works against him; while Marth only had some degree of disadvantage in Melee on Dream Land, Project M introduces similarly large stages that Marth struggles to KO on, while relegating his previously best stage, Final Destination, as a counterpick in most rulesets.
Changes from Melee to PM
Marth was slightly buffed from Melee to Project M. His down aerial, previously a risky move to use on-stage due to its landing lag, now has much less lag. This allows it to be used more effectively as an out of shield option, and makes it a more reliable punish starter on characters in a knockdown state. The changes to stale-move negation also benefit the damage potential of his neutral aerial and Dancing Blade slightly. Aside from changes regarding mechanics and angle alterations, most of which benefit him, Marth remains relatively unchanged compared to other top-tier characters in Melee.
Grabs and Throws
Up to date as of version 3.6.
For simplicity, if, for example, Marth's blade does 4% damage while the tip does 6%, and the attack has no other hitboxes, it is written as 4%/6%.
In competitive play
Marth once again uses his default costume when fighting on the blue team, so his blue costume was changed to purple. 3.5 included a set of alternate costumes based off Sigurd from Fire Emblem: Genealogy of the Holy War, which includes recolors for team battle.
The recolors of the Sigurd costume resemble other characters from Genealogy of the Holy War, specifically characters closely related to Sigurd: