Factorio Minimum Resources TAS

Most speedruns try to complete their goal in the fastest time. Others minimize space or have other limitations for extra challenge, and they all use some really clever tricks to accomplish it. I, however, have problems, so I'm not doing any of that. I instead ask a different question: what is the absolute minimum amount of resources you can dig out of the ground and still beat the game? I saw the question going around r/factorio and the forums a few years back and it stuck with me for reasons I'm not sure I can explain even to myself. Those posts do give numerical answers but as far as I know they've never been proven with a run, probably because other people are still sane enough to know it's a dumb idea

How-to

• create a tas.TAS object
• define various tas.Tasks, task.Prerequisites().Add() if needed
• tas.Add(tasks) and check for errors
• tas.Export(outFile) to write the Lua code, save it to mods/MinPctTAS_0.0.1/tasks.lua (alternatively, just run make from the directory containing this README)
• make start_factorio and create a new map with the string in SETUP.md

FAQ

Definitions

• "beat the game": launch a rocket. Instead of time, we're minimizing the sum of the resources on the production tab
• "resource": anything you can mine. For vanilla, this means wood, stone, iron ore, copper ore, uranium ore, and coal. Water and crude oil are excluded primarily because they make the math far more difficult for little perceived benefit

Does this work with mods?

Yes. I'm using Factorio's own mechanisms to dump the data it uses, so there's no practical reason it shouldn't work with your mod(s) of choice, although I will disclaim that by warning that recipe cycles are not something I'm prepared to handle yet so things will get weird if you try to use a mod that has them. Technically vanilla has them too but nuclear and coal liquefaction are both strictly optional so it doesn't matter for what I'm doing

Does this work with another map?

Yes. There's nothing special about the seed I chose aside from it having a good layout. Just be sure to update locations.lua in the mod

But how does it actually work?

Short answer: it's a mod and Go command that takes some abstract tasks and turns them into a TAS.

Long answer: I've written a mod (based on https://mods.factorio.com/mod/AnyPctTAS but heavily modified to do what's described here) to take a series of tasks and perform them in order. Instead of the original mod hardcoding the order and which tick they're performed on, this allows you to set prerequisites that must be done before a task is started, so you can have something like "craft 10 iron-gear-wheels but not before you take 20 iron-plates from the furnace." The mod considers a TAS "done" when there's no more tasks left to perform, and it'll print out how many resources were used in the process.

The tasks are split into three queues:

• character_craft for handcrafting
• lab for research
• character_action for everything else, like mining or putting stuff in machines

On each tick, the queues are checked in the order listed above (only one is started on any given tick). If all of the task's prerequisites are done(), the task is started and marked as such. If a task is already running, we check if it's done(), and if it is, the next task is pulled off the queue. Some of the character_actions also need locations, but for the purpose of easier script generation they are not hardcoded anywhere in the Go code; The building name and, for those we build more than one of, index are used and the "real" location is found at runtime via the logic in locations.lua.

tasks.lua can be modified directly, but an easier option is to use the Go command I've also provided. That allows you to define goals more abstractly (and handles defining prerequisite actions in an automated manner). It works in a couple of phases

• define some Tasks using the provided functions (eg, tas.Craft or tas.Tech)
• create the dependencies using task.Prerequisites().Add
• create a tas.TAS and Add the tasks you just created. The returned error will tell you if the run is valid
  • this works by (a) checking if prerequisites appear in the right order, and (b) performing the state transformations provided by each task and verifying that they're possible in-game
• call tas.Export to write the generated Lua code, which should replace mods/MinPctTAS_0.0.1/tasks.lua

What modifications are made to the game?

Aside from the obvious "character is being controlled by the script," I've also made a couple other changes for convenience. They don't affect the quantity of resources required but they do make the run faster to code/execute.

• night does not exist. This is because most of the run has machines powered by one solar panel
• character inventory size is greatly increased. This is also not necessary, but not doing it would require that I implement logic to drop things on the ground and pick them up and that seems like more trouble that it's worth
• character reach distance is increased. The compact build this run uses contains a "cage" of pipes that would be incredibly annoying to walk around all the time so we just don't

Just how painful is this?

Extremely. Mining drills and machines and extensive power setups are extra resources that don't need to be used, so everything is hand-mined (steel-axe is also not necessary and won't be researched), and every craft is either done by hand or in a machine that's powered by one solar panel. Just to give you an idea, the run in main.go researches the productivity-module tech and builds a basic oil processing setup and takes nearly 17 hours of real-time to mine, smelt, craft, and research it all. The run from there will be mostly using underpowered machines (to take advantage of prod mod bonuses) so I won't be surprised if it ends up being hundreds of hours in total. Granted, there is definitely room for optimization but that takes effort and it's hard enough getting anything to work

LICENSE

All code in this repository is licensed under the terms of the GNU General Public License, version 3 (or at your choice, any later version). See the LICENSE file for more details