Firstly, here's a demonstration of what a regular slam cooldown looks like (first two swings), and what bypassing the cooldown looks like (next 3 swings). Put into words, a regular slam should result in you kneeling down for a second after hitting the ground. It happens after you jump and punch, or if you fall farther than regular-jump height. What you see after I show the cooldown is a way to bypass it - standing on an elevated object/platform, walking in any direction dropping down (without jumping), and hitting the attack button midair. If you time it correctly, you will land on your feet without suffering any cooldown and are able to continue your regular punching/kicking combo as usual.
The same can be done with kicks. Again, I demonstrate regular kick cooldown in my first 3 attempts, and then show how it can be done without getting kick cooldown. My last attempt shows how this can be continued with a regular punch combo. Don't think it's fast? Here's what a regular button-mash kick pattern looks like (with its cooldown). ---
Putting this all into perspective, you could use the no-cooldown kick trick to stagger an opponent into a long drop by standing on an crate/barrel, kicking once, moving in their direction, and kicking again while midair for another push towards the edge. Alternatively, kick once, move, punch midair for a no-cooldown slam, and continue with a regular 3-punch combo for massive melee damage.
This gets worse if you have a melee weapon. A heavy one, like a fireaxe. Here's what a no-cooldown slam looks like on a bot. Imagine doing THIS, with a strong melee weapon, multiple times in a row. Suddenly you're easily chipping off 15-30, or even MORE health off of a poor player who can't react to your attacks (player gets up only after the 2nd hit). Even if they do manage to escape, the damage dealt makes it easier to kill them later or makes them easy prey for the other opponents.
Oh, but there's more.
These tricks can be used with platforms! You see, the no-cooldown trick works when you're
- a) midair
b) when the fall height isn't big enough to result in a cooldown.
I'll explain why these methods are broken and can't be masked as simply "using the terrain to your advantage" again.
Cooldown was introduced to prevent
- a) spamming these moves without consequences
b) prevent fast movement and melee "hit-n-run" tactics.
You can fix this by introducing cooldown for both kick and slam regardless of drop height. It would surely slow melee down further, but that's a result of keeping broken mechanics in-game rather than introducing new ones and developing new combos or movesets, and has nothing to do with this thread in particular.