This Block Isn’t Real…but why?

Minecraft is a huge game not only in how much content it has but also in its community and variety a block game that anyone can pick up and enjoy but equally a game with many misconceptions and mysteries because of minecraft’s large community and constant updates it always seems that compared to other games

Minecraft is full of the weirdest bugs and glitches some are so popular they eventually become features while others are so detrimental to the gameplay they need an entire update just to get patched but there are a few minecraft quirks that just seem to baffle me which is so strange that many of their

Own different ideas of what they think is going on one of the most famous misunderstood glitches being zero tick pistons with lots of players thinking had been removed in 1.16 when zero tick farms were patched those people i say you’re done today i hope to finally give a proper

Explanation to one of minecraft’s oldest bugs this bug is so old that there’s been an attempt to fix it in almost every single update a bug that makes minecraft blocks that don’t exist Now before we dive into an explanation of what a ghost block is we need to know what a ghost block isn’t a lot of you when hearing the term ghost block might immediately think of something else lock 36 while they share similarities like uh yeah they don’t really share that many

Similarities block 36 is not a bug and is an intentional feature of the game and part of the pistons extension process the term ghostblock doesn’t come because the block in question was invisible but because ghost blocks technically don’t exist here’s a very common example of these ghost blocks in action if you’ve

Ever played a large server like hypixel and played a game like bed wars with fireballs and tnt destroying large amount of blocks you’ve probably been in the annoying situation where you’ve been stuck in a ghost block and the only way to free yourself was to spam right click

And hope that the block you were standing on would appear but why does this happen well the whole reason that ghostblock existed in the first place is that there was a desynchronization between you the player or the server’s client and hypixel or the server you are connected

To in our bed wars example the surface says hey there should be a block there the player shouldn’t be able to move through the block but the client says hey wow there isn’t a block here i should be able to walk through there’s a long time the jitter motion

Can be blamed on the server and the client basically playing tug of war on who has the right information when you spam right-click to update the blocks you make the client realize wait there were blocks here the whole time and then you’re able to break free

This is an example of a block only existing on the server but not the client and the less useful and more annoying kind of ghost block you can get but what happens when you do the opposite what if the block only existed on your client but not the rest of the server So you you see this wall a very normal looking wall right yeah i can’t run into this walls looks pretty abstract yeah i can’t get the horse in the wall yeah it makes sense there’s a wall there i have some other things to test for walls so we’ll grab my wall testing

Materials you know as normal walls you’re able to throw pearls through the walls and if i want that villager to come over i can that’s just a thing that you’re able to do with walls you know no it’s not that’s not a normal thing this new

Walls you can get a zombie to come and oh and he came through the wall oh there’s a pig through the wall you know but i thought this was a normal wall you know like it’s a completely normal wall wait what i don’t know what to believe anymore

So misty cat this is a wall uh quite smooth a little bit quartzy it’s a very legit wall he is just lighter and you know i can i can summon him through this wall that’s a normal wall thing to do for sure i have other normal wall things over here for example

I can throw my ender pearl across this wall right here because i don’t like the wall but in the way there yeah it’s a bit of a cringe wall oh my god where’d the wall go probably off to get milk like my dad crafty mastermind what the heck is

Happening here well these are still ghost blocks and still the product of the client and the server not being quite in sync in this case the client says whoa look at this sick block over here well the server is totally oblivious to what’s going on and thinks there isn’t a

Block in that position unlike the other version of the ghost block these don’t conflict with the player and you don’t get that annoying jittery motion but it does have some funky properties with other entities like minecarts projectiles items and mobs if you do make these ghost blocks on a multiplayer server other players

That weren’t around the area when the ghostbots are generated will just see a floating player on invisible blocks and since the server thinks you shouldn’t be flying if there are anti-cheats on it there’s a chance you can be kicked if not banned but the best part about these

Ghost blocks is how they update pushing ghostbots with pistons you can replace an entire wall and right clicking it will make the blocks change to their original state meaning now with enough creativity you can make an interactive touch screen so let’s see what i’ve made first off we have

Battleship with screens on either side players replace the blocks where they want their ships to be and once they are hidden they take turns right-clicking positions on the board to try and expose the enemy ships next up we have mine sweeper similar to battleship the player right-clicks spots on the board to

Slowly reveal the location of the bomb if they see a leaf a log is placed to expose all the other squares with nothing on them and then we also have tic-tac-toe and hangman which still have these same right-clicking interfaces pulling away all the fancy decoration this is what the redstone looks like so

How does it actually work special thanks to spacewalker for all of the ghostblock nerdy knowledge his channel will be in the description if you want to check him out so let’s start with a fun fact even if you play on a singleplayer world your minecraft game still runs an internal server both your

Server and your client have a copy of your world with the server basically doing all the heavy lifting while your client is just kind of chilling waiting to receive any information however some things the client does process are player controls rendering interactions with the world and piston the server decides when the

Pistons should push whether it’s given power with redstone or maybe it can’t push if there are movable objects in front of it but both the server and the client process the pistons push and pull logic each tick the server does dozens of different processes and checks but there

Are three that matter to this specific ghostblock generator tick chunks which includes many different things but the only part we care about is where it sends block changes to the player executes scheduled lock ticks which in this case controls the dispenser placing and scooping the powdered snow and

Process block events which is the pistons extending and retracting in 1.17 these three events were placed in this order first we get tick chunks which won’t do anything since neither the piston or the dispenser have been powered execute scheduled block ticks comes next which means the dispenser

Will now scoop up the powdered snow but guess what the client is a lazy bum and doesn’t realize that until tick chunks occurs again the next time this loops and finally process block events happens which extends the piston on the server the piston has nothing in front of it

And it just pushes air but the client doesn’t know that yet and the piston pushes an exclusively client-sided powdered snow block as well as pushing any other blocks in front of it ah they fixed it so let’s go through the loop again and see how this change fixed

The ghost block issue first we get execute scheduled block ticks the dispenser scoops up the powdered snow now we get tick chunks which will send the information to the client that the powdered snow had been removed and finally process block events will happen extending the piston which now has air

On both the client and the server preventing a ghost block from being generated tldr they switched two lines of code subscribe