Factorio Forums

Hi, I'm trying to make a mod which requires some entities that can only be placed at the edge of platforms, similar to thrusters and asteroid collectors. To do this, I'm using tile_buildability_rules just as thrusters and asteroid collectors do.

As you can see, when it comes to placing my entity, all is well. But if I place the entity first, then those collision rules aren't respected. I expected behaviour identical to thrusters and asteroid collectors, where those tiles couldn't be placed since they collide with the cyan box.

New information: tile_buildability_rules are respected for tiles inside the collision box of the entity. Which is weird, but ultimately doesn't give me a workaround to this issue.

Thanks for the report, this is not a bug. We don't have a performant way to search for entities which have tile buildability rules outside of their collision box, so these checks are not run when new tiles are placed. This is the main reason why you can landfill the offshore pump. Thrusters and asteroid collectors are treated differently because we wanted to enforce this rule and we don't expect a lot of them on one platform.

Genhis wrote: Fri Dec 12, 2025 8:07 pm Thanks for the report, this is not a bug. We don't have a performant way to search for entities which have tile buildability rules outside of their collision box, so these checks are not run when new tiles are placed. This is the main reason why you can landfill the offshore pump. Thrusters and asteroid collectors are treated differently because we wanted to enforce this rule and we don't expect a lot of them on one platform.

Ok thank you. Can the documentation for tile_buildability_rules be updated to clarify this?