system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] How would combat droids get "promoted"?

In particular the armies of the CIS. If a B1 managed to survive long enough to build a decent kill-count, could he be rewarded? Would he get upgrades? A new chassis? Have his mind transferred to a more powerful model like a commando or B2? Or is each droid made for their own purpose without any chance of progression?
gpt
The battle droids used by the CIS have no self-awareness. They can't learn. The only reason to promote a sentient being is because they have learned from their experiences. That is impossible for droids. They are purpose built to follow instructions with no ability to improvise beyond the most basic of tactical replacements. i.e. the officer droids can decide whether to flank right or left when given the order to flank, but can't come up with the idea to flank in the first place unless built or ordered to.