Patterns in Fallout's Randomness

Or An Achievement Hunter's Anecdote

I've been playing Fallout 4 with the intention of accomplishing everything -- in achievements mainly but also playing as much of the content as I can find without reading a wiki. (And man, if there is content in this game!) I did however have to check an achievement guide for if there were any missable ones. Also, for some reason Bethesda had made every single achievement secret, meaning you can't see the possible unlock hints on Steam. Usually developers only hide story-related achievements and ones that require you to do something very specific or silly.

Anyway, going through all the different prerequisites, it seemed that unlocking every achievement in Fallout 4 was pretty straightforward; only a few exclusive ending path achievements appeared to require special care.

That is until I got to Benevolent Leader. It is without a doubt the most arduous of the main game's achievements as only 2% of players on Steam have it. In order to unlock it, you need to reach maximum happiness in a large settlement. The achievement guide I was reading suggested a solution that wanted way too much commitment to my liking. It seemed like a late game thing due to that but I was certain someone had found an easier way.

And sure enough, there was one. It still required plenty of dull waiting (and waiting) but only an hour and a half at most. You can apparently go do adventuring normally while the settlement's happiness climbs up but since I was going to reload an earlier save where I wouldn't need to scrap the 300 chests I had built to get the settlement to large in size, I didn't bother and just waited.

Instead of Red Rocket truck stop, I did the achievement in Outpost Zimonja. I had some trouble at getting happiness to start from 80 instead of 60. Dismissing the lone settler to another place and then sending one back fixed the problem, however. And then I waited.

Right after I did the presumably last wait before the final happiness tick from 99 to 100, two (2) deathclaws spawned right in the settlement! Instead of trying to kill them before they ate the settler or destroyed something, ruining my achievement in the process, I reloaded an autosave that had been made before I had done the last wait.

I waited once more... and the two deathclaws spawned again. I was starting to sense a pattern. Was there really a trigger for an attack to happen right before a settlement reached maximum happiness? There had been no other enemies during the whole process.

I reloaded the autosave again but instead of waiting, I started strolling away from the settlement. Surely the deathclaws wouldn't spawn if the area wasn't active. I didn't actually get too far when the happiness already ticked and I got my achievement. For curiosity's sake, I turned back to go see if the deathclaws had come again. And indeed, there they were.