Factorio Forums

How to allow an entity (with an area larger than one tile) to be built on lava and ground simultaneously, but forbid construction on all other tiles that collide with the water_tile layer?

Take a look at the tile_buildability_rules for the offshore-pump to get started; you need to define multiple rules for the different areas of your entity. It looks like you just need to set lava_tile=true instead of water_tile=true?

Good Luck!

eugenekay wrote: Tue Jul 07, 2026 12:17 pm Take a look at the tile_buildability_rules for the offshore-pump to get started; you need to define multiple rules for the different areas of your entity. It looks like you just need to set lava_tile=true instead of water_tile=true?

Good Luck!

Thanks for the reply! The main issue is that the lava tile has in its collision mask, along with several other layers (like ) that overlap with the entity's standard collision mask. Testing all these combinations one by one takes a lot of time, which is why I was hoping to get advice from more experienced modders.

In short, I want the entity to be placeable on both and lava, but absolutely forbidden on water. Since lava inherently carries both and masks, standard masks conflict. Additionally, the entity must collide with the layer only on ground tiles, but not on lava.

To put it roughly in pseudocode:

• ALLOW placement if: (lava OR ground)
• FORBID placement if: (ground AND item)

How can I configure or collision masks to achieve this specific conditional behavior for a 4x4 entity?