Ok so I've started work on my own VAC for a fun little project so I thought I would make a thread about the pros and cons of these types of anti cheats. NOTE: VACs are still a very new concept that has only really been possible sine the 1.9 release I only know of two servers that have a decent VAC as very few people work on them. Lets start with what exactly a VAC is A VAC (vanilla anti cheat) is an anti cheat ran completely off command blocks. They are now just recently being created as new 1.9 command block features allow for many completely vanilla mini games servers to be made. Even things like eggwars, skywars, dueling, and money walls can be made in vanilla now. As soon as all these servers started coming out they were a prime target for hackers so server devs needed to use what they had - command blocks - to stop them The results of these anti cheats can vary but done well I have seen a vanilla server with an anti cheat far superior to cubecraft's current anti cheat. Pros: Lets start with the good then the bad 1. Nearly impossible for clients to negate Most hack clients change nbt tags to work and avoid anti cheats. Back clients can not change scoreboard values so the these anti cheats are fool proof if done well. 2. Pretty easy to make These anti cheats don't take nearly as long to make as a plugin as they usually don't take more than 60 command blocks at most. 3. Easily customizable Since these anti cheats are so easy to make you can also very easily tailor them to your specific server. Server doesn't have any way of getting jump boost? Well you can buff your anti cheat now that it doesn't need to account for that. 4. Completely vanilla Obviously these are completely vanilla And let you get your server into the vanilla part of various server list websites which usually have very little competition giving your server a higher chance of succeeding. 5. Just plain cool Not much to explain here Now for the cons oh boy... 1. Limited use inter dimensionally Command blocks don't work that well across dimensions meaning your VAC won't work well if at all in the nether/end. 2. Laggy Without the proper command block techniques to reduce lag these VACs can be incredibly laggy especially if you have long chains that are constantly running. Only a problem for complicated anti cheats that try to do it all 3. Affect legit players It is very hard for a VAC to not pick up on someone with bad connection also there are very few ways to detect kill aura using only command blocks and the ways that do often pick up on skilled players. 4. Very weird You can't use /kick or /ban with command blocks so you have to do some very weird work arounds to accomplish these things (Im going to keep it secret now as the vanilla server owners might want to do so) 5. Take up space VACs must be in your spawn chunks or else they won't work properly so they take up a very important part of the world. 6. Require constant updates You probably won't have to change your entire anti cheat once a new update comes out but command blocks formatting changes happen all the time and this can easily break your anti cheat. 7. Some hacks are impossible to detect Hacks like noSlowDown, fast eat, trigger bot, and freecam are nearly impossible to detect with command blocks as of now. Future mc updates will come out with more scoreboard objectives that can be used though. Again as I said VACs are very new and still have a ton of room for improvement. Already they can do better than nocheatplus and have only been possible for a few months. While a lot of the methods are secret to the vanilla mini games server owners only more and more people will eventually work on them making better and better versions I hope to have my own VAC done by the end of the month so hype? Thanks for reading!