What's the most efficient way to obtain XP from 1.12 - 1.14? [duplicate]
The fastest XP farm possible is an enderdragon XP farm. This may sound ridiculous, but people have actually built them, even in Survival.
The reason why it's the fastest is that you can only collect a small amount of XP orbs per second and the dragon drops XP orbs with higher value than any other mob, block, etc.
The reason why you can get a constant stream is that the dragon doesn't save how far it is in its death animation when it's unloaded and loaded again, so you can make it die and drop XP over and over again. And since 1.9 that even makes additional dragons spawn for some reason, so the farm gets faster and faster the longer you use it.
The latest design I was able to find should work in 1.12, but the bug it relies on is still in the game and maybe even the entire farm design still works for 1.13. But 1.14 has severe chunk loading issues, so I don't think any farm works properly in 1.14, or any machine at all.
And yes, you can use that XP to enchant things, just enchant it in the End and put it into an ender chest before jumping into the void. If you never let the first dragon die fully, you get even bigger XP orbs.
While Fabian's suggestion of Ender Dragon farm sure beats the rest in terms of raw XP output, it's simultaneously an enormous amount of work to build, takes time to start and shut down properly, and the ludicrous efficiency is absolutely pointless. It only makes sense for the bragging rights.
The practical solutions:
- Ender farm, in particular Gnembon's EnderMini - easy to set up, quite efficient, requires player interaction (but produces so much XP you can take your time to enchant/repair stuff in between slaying the endermen as player's absorption of XP balls takes time). Overall a great trade-off between efficiency, convenience and difficulty of construction.
- Guardian farm - only if the drops matter. It's a lot of work to set up, and the output is similar to that of an Ender farm (although depending on location in the overworld it may be more conveniently accessible.) Choose only if you want to focus on prismarine / sea lanterns drops. Also, requires constant slashing the guardians with a sword, and preferably a regeneration beacon (or a lot of food) as you'll be taking damage.
- Pigmen farm on Nether top. Moderate/high effort, but very convenient - slightly worse efficiency than others but you only need to shoot one pigman to start it up, and then you can stay afk and collect XP, or busy yourself with enchanting while XP keeps coming in. Also, produces lots of gold.
- Furnace array - Instant injection of XP, but takes a long time to "charge up". Awesome for quick repair of gear, not good for lengthy enchanting sessions as the furnaces take several in-game days to replenish the XP. Quite easy to build but depending on fuel may be space-intensive (e.g. requiring a big bamboo or kelp farm).