I've been playing various kinds of PvP for about 2 years, from strategic custom maps to potion PvP to UHCs to minigames, and probably have around 1000 hours of just that. I wouldn't have kept doing PvP for so long if it wasn't already fun. I have a good idea of what will work and what won't.

Things to keep in mind while adding things:
* Minecraft isn't a fighting game set on a static flat ground. It's a dynamic world with a lot of variety in scenarios and sizes, including those made with terrain generation, arenas people have made, and things built during or just before the fight. You can build cover, pillar up, tunnel into a wall, block off enemies' paths all during of a fight. * How will people abuse this new addition to win? If you add parrying by blocking at a certain time, will that turn sword fights into a mess of spamming the block and hit buttons until someone gets lucky? If you make backstabbing do more damage, will sword fights involve trying to stand inside of the others' hitbox and swivel around? It has to be both skill-based and fun for any skill level. * Nothing added should be counter-intuitive to someone who's just learned the controls for the game. A lot of people are suggesting to make it just like Chivalry, but that makes no sense when every other item only has two functions; hit, and right click action. * The entire movement of the game is very simple, quick, and responsive; there's very little acceleration in walking, jumping has gravity 2-3 times that of real life, block placing is instant, switching hotbar slots is instant. None of this should be comprimised for combat, and this type of controlling should be applied to combat as well. * Just because the majority thinks it's a good idea in theory, doesn't mean it's good in practice. Most people who read this very rarely play PvP, and if their radical suggestions are implemented, they probably won't play it much more than they do now, but it will still have a big negative effect on people who already play PvP a lot. A lot of people have their bags packed and are ready to leave the game if this gets screwed up. * Melee combat is way more skill based than you think it is. It's not the most skill based, but the current simplistic fast-paced knockback-based system is the best fit for that dynamic world thing I was talking about earlier. It's quite ping based, but I'm not a developer, so I can't tell you how to fix that. * It's not just sword and bow. Blocks, ender pearls, flint and steel, lava buckets, water buckets, fishing rods, snowballs, and TNT all have various uses in PvP. This is still a sandbox game. * Good for PvE doesn't mean good for PvP. I would prioritise PvP over PvE, because probably there's less people who mainly play PvE than people who mainly play PvP. * Randomness in both PvE and PvP is very bad. It never feels good when you should have won, but didn't. Same action should equal same result.

Actual suggestions:
* Remove any randomness from enchantments. It's not uncommon to have two people shoot each other and one shot to do three times the damage. * Make bow shots not have a random spread, and make it shoot from the exact centre of the character, unless it obscures vision. It's hard enough to land 70 block shots, we don't need any extra factors to it. * An enchantment that lets arrows shoot through water with no slowdown. * Nerf knockback enchantments. The current knockback/punch 1 feels like it should be the strongest it can possibly go in survival. * Nerf strength potions. Wooden sword + strength 2 = sharpness six diamond sword. * Fix armour not flashing red when you take damage. * Get rid of zombies randomly not taking knockback (this is apparently a feature, not a bug), reduce the damage/health of baby zombies, and get rid of zombies being able to summon other zombies directly into your face. * Remove jump crits, at least against players. It's actually kind of random because someone hitting you will launch you upwards so you can do more damage falling down. Critting normally is really ineffective, because being in the air makes you take more knockback. Overall it just serves to add more unnecessary random damage. With PvE, it's fine as it is. * Revert the TNT flowing in water bug fix. It requires inhuman timing to consistently fire in the same spot, and the particular timing might be so fast that it blows up midair anyways. For automatic cannons, it's extra calculations, and timing won't be a variable anymore. Because cannon destruction isn't based on the force at which it hits something, there's no real advantage of water pushing TNT. * Potion duration, and maybe armour/tool durability HUD outside of inventory screen. A lot of people use mods to do it. It gives an advantage having it, but I don't see a problem with everyone having it. It's like BetterSprint and the sprint key back in the day (except not really, see next point). * A server option for disabling sprint key (which most serious PvP servers will use). It might be weird to do this now, when everyone's gotten used to the sprint key, but double tap made melee so much more skill based. Unlike with the sprint key now, it takes skill to knock someone back, then sprint to catch up to someone, then hit them again. Even the old wobble sprint glitch when you triple tap instead of double tap is good, because it punishes you for spamming W rather than hitting it twice. * Double tap sideways to dodge, but it has to be done very right. It can't be faster than sprint-jumping, or people would use it as their main method of moving fast, regardless of things like hunger. If there's a cooldown, it would be hard to tell when it ends, and just become random to most people. Not to mention it would be easy to accidentally trigger and throw yourself off of something. Maybe make it only work when you're holding sprint key. Also, not while doing anything that would normally slow you down, like eating or drawing a bow, otherwise the speed penalty is basically gone. There a lot that could be messed up by this addition, so if it doesn't work out, just scrap it. * Some client-side cheat prevention, either to make it much easier for servers to tell if someone is hacking, or to make it much harder to create hacks.

Things I'm specifically against being added:
* Anything that involves random number generators. * A lock-on system. I hope the reasoning is obvious. * A bow enchantment that makes arrows fall less or move faster. You can already hit targets 100 blocks away, there's no need to just make it easier. * Removing or reducing player knockback. Right now it's properly balanced so that hitting someone back is roughly the same speed as you running forward. The environmental hazard of being knocked off a cliff or into a lava pool is a big part of PvP. * Most sidegrade ideas. Regardless of what it is, people will always find a "best" combination of gear, and will always use it, regardless of how fun fights are with everyone using it. * If you for some reason decide to make fancy armours the let you go faster, make it so the light armour increases your speed, not that heavy armour decreases your speed. * Splash potions as long ranged weapons. They are very much usable in their current state. You use them while standing still/running back as someone is running towards you. With how much damage these things do, It's fair that you have to take a risk when using them. * Parrying. It sounds like it adds depth, but I don't see it being implemented in a way that's balanced and skill-based. Hitting is fast, and has no wind-up, so again, more randomness. If you add a wind-up, it'll either be so long that the combat starts feeling sluggish, or too short to react to (and still feel a bit sluggish). * Different damage depending on where you hit the player. It could add a lot of skill, but I see a lot more scenarios where it's just a random crit. Overall, it's going to do more bad than good. * Extra backstab damage. It'll turn into people trying to get inside each other and turning to get the cheap backstab. Sneaking up on someone is enough of an advantage already. If you sneak up on someone, and they still kill you, they deserve the kill. * Dual wielding. Mostly because it would be completely useless with how the damage cooldown works right now. If you wanted to switch between two different weapons with different attributes quickly, you can hotkey. * An enchantment that decreases bow draw time. It'd have to be a very low amount to work. Whatever the strongest enchantment level is, will become the "default" form of bow PvP. I like how slow paced it is now, because you have time to think about strafing, and predicting where they will strafe next. If it's too fast, it may become too hard to do that. If you do add it, the fastest drawback time should be ~70% of what it is by default. Don't increase the default draw time. That's not a fix. * Fixing the bug of extra knockback from sprint restarts. Right now, if you keep hitting someone while holding down your sprint key, you'll do extra knockback once, then normal knockback. But if you disable and re-enable your sprint between hits, you'll do extra knockback. You can do this by tapping sprint instead of holding, blocking your sword between hits, tapping sneak button between hits, or by using double tap W to sprint. Hitting someone, even during their invincibility period, stops your sprint. This makes it so you can't just click fast to pull this off, and have to time it a bit. Maybe I'm just uncreative, but I don't see any better/more skill based way of having a system for dealing extra knockback, even if it's unintentional.

TL;DR: Don't add things for the sake of adding them, keep everything as similar to the main game as possible, randomness in combat is bad, emphasizing skill is good, put more weight on the opinions of people who are experienced with PvP than those who mostly play survival.