Factorio Forums

TLDR

When I CTRL click in my inventory with a machine open such that the machine has modules, the modules get downgraded instead of upgraded.

Note: I have not tested this with every module type, only quality modules.

Details and example

Tier 2 uncommon (and better) modules have a higher quality bonus than common T3 quality modules (uncommon T2 => 2.6%, rare T2 => 3.2%, common T3 => 2.5%)

I have an assembler that has some quality modules in it, and I CTRL+ left mouse button in my inventory, the modules get automatically updated to be the best I have in my inventory. That's an intended feature to make upgrading modules easier.

However, the game prefers modules of a higher tier, even if they are worse than quality modules of a lower tier.

I tested this only with quality modules (on another planet and don't have quality modules of a different type with me), but the game wanted to replace my rare T2 quality modules with my common T3 quality modules, which resulted in a worse overall quality.


As you can see in the images, it also does it based on order - since I had an epic T2 in the first module slot, it put in a T3, and didn't keep the epic.
(I only have 3 T3 modules in my inventory, hence why the last T2 didn't get replaced)

CTRL + LMB again replaced the rare T2 with the epic T2, which is expected.

EDIT:
By chance, I discovered another interesting quirk -
Let say I have a machine that has 5 T2 uncommon modules. In my inventory, I have 3 rare T3 modules, 3 common T3 modules, and 3 rare T2 modules. (all quality modules).
If I CTRL + LMB, the correct modules get put in - the 5 uncommon T2 modules get replaced with 3 rare T3's and 2 rare T2s. However, if I CTRL + LMB again, the rare T2's get replaced with common T3's as described before.

What it should do:

I think the order for quick-upgrade modules is incorrect. It shouldn't be blanket "tier, then highest quality', but it should check the numerical values. i.e., in this case, since an epic T2 quality module is better than a T3 quality module, a quick upgrade should replace a T3 common with a T2 epic, and never the other way around.

This is not a bug, make a feature request.

kk, got it, will do! Thanks for letting me know!