In a recent post on planting alchemy ingredients on TerrariaOnline there is a mention of multiplication of lava. The post states the following:

this blackened area is the "temporary" Lava multiplication wing. It can be made longer if you want to, but it works the same: put the lava near the one-block high wall, let it pour for a bit, and after pick it back. In contrast with the water multiplication, you need to wait a bit, whereas waiting when multiplicating water, will result in a slow water-generating process.

This seems to indicate that there is a way to duplicate lava and water somehow. The instructions above seem to require some familiarity with that feature already, or at least they are not entirely clear to me.

Is there a way to duplicate lava and water in Terraria? If yes, how can it be performed?


2 Answers 2


The liquid physics in Terraria are not completely precise. You can abuse it to duplicate them. Good thing, too, since transporting a decent amount of lava/water anywhere is a huge pain.

  1. Infinite container: If you make a liquid container large enough, the amount that drains each frame is rounded down to nothing, for some reason. For example, a 49×25 liquid container with a 1 block hole will create an infinite amount of liquid (video example of this). This will break if liquids are settled (via the server console or when saving and loading the map).
  2. Liquid splitting: When a liquid falls onto a single block and could flow down both the left and right edge, it will. Somehow, this leaves you with more liquid in total than you started with.
  3. Bucket weirdness: Buckets create 1 block of liquid when they're emptied, but filling them seems to require less. If you place a block, let some of it flow and then quickly pick it up again, you will have a full bucket, but some of the liquid will remain.

Applying #2 and #3, this is a very simple liquid duping setup:

Simple liquid duping setup

The lava is placed on the edge, where it flows into both the container and the 1-block "basin" on the right side. Both "portions" are enough to be picked up by a bucket again (though in this case, the first scoop will be spread too thinly in the container).


Due to the way fluids are coded, both water and magma seem to 'multiply' when they flow down a series of blocks. Though I don't know why this happens (look to someone who has poked through the Terraria code, for instance) I can show you how to do this.

enter image description here

Here is what I call my Lava Accelerator. It is a series of downward steps with a large pit at the bottom to collect the resulting fluid.

enter image description here

To begin, you grab some lava from the trough here, and put it on the lip of the lava trough. The lava will pour both left and right, with the left going back into the lava trough, and the right heading into the lava acceelerator proper.enter image description here

At the bottom, the lava has collected. After falling down these stairs, one bucket of lava...

enter image description here

...has turned into more than four.

If you do this repeatedly, you can quickly fill even the large tank (which I've hooked up to an obsidian generator).

I don't know the particulars of fluid splitting, so I may not have the most efficient of infinite fluid splitting, but hopefully this explains the principle well enough.

  • i wonder if instead of two stair cases, you made a massive lava pachinko machine you'd get even more
    – jk.
    Jul 13, 2011 at 20:27
  • @jk - I wondered the same thing. I've yet to bother with testing it, however. Jul 13, 2011 at 20:42
  • I actually stumbled onto the stairway idea after I accidentally dropped a bucket of lava down the vine covered tunnel at the left of the final screenshot. I had a massive lava pool after only dropping a single bucket, so that was the Eureka! moment. Jul 13, 2011 at 20:59
  • @jk I tried the lava pachinko idea, and the lava would only split so far before it stopped and got stuck between two posts. Adding more lava would wash it all down, but it seems there's a limit to how much the lava will increase without recombining it before splitting it again.
    – Fambida
    Oct 23, 2011 at 12:15

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .