An early engineer will help you quickly start clearing space for your first two buildings. I recommend reloading a previous save until they spawn an engineer on the map in those first few days. The first few scanning locations are randomized. *** Spoiler - click to reveal *** It is very important to get off to a good start. March 30 - Proving Grounds Project Completed: Skulljack March 22 - Construction Completed: Proving Grounds March 21 - Mission: Investigate Blacksite March 10 - Lab Research Completed: ADVENT Officer Autopsy March 05 - Lab Research Completed: Alien Biotech That being said, I am sure this type of outline will prove useful to a number of people.

I'm sure there are dozens of ways to approach this achievement and your results may vary. I took my foot off the gas a bit in month four to spend time researching additional armor and weapon upgrades, as time allowed. I ended up finishing all of the critical projects and missions with about 10-15 days remaining. You won't have much time to spare on building a GTS school and you certainly can't be spending time training new soldiers to replace the fallen. This didn't end up being much of a handicap at all. I played on Commander difficulty and chose to simultaneously obtain the achievements for never buying a squad size upgrade and the achievement for never losing a soldier. This is a log of my activity with the exact days that I completed each of the important research projects, construction projects, and missions along the critical path. I thought it might help people to see a sample timeline. You will need to plan out your research and construction goals, ignoring most upgrades in favor of the mission critical projects. The goal of this achievement is to beat the game on Commander (or Legend ) difficulty in under four months.

Xcom 2 mission difficulty