system
Given the following post, respond as if you're commenting on Reddit:
human
[Halo] Why didn't the UNSC make and use robots and drones to battle the Covenant?

I was just wondering if there was a specific reason as to why they didn't utilize the potential resource of robots. A smart A.I. could have possible operated hundreds of robots to fight. With the A.I. in them the robots would have been super intelligent, fast and depending on the build of the bot extremely strong.
gpt
Mostly its the power issue. Spartan II armor, mark IV and up, is powered by a compact nuclear fusion reactor to power both the suit and the suit's shields. The earlier models needed to be plugged in in order to get enough power to just operate the suits. That's the issue with robots, the cost of the fusion reactor is just too damned expensive to mass produce. Without a powerful and durable energy source a robot army just isn't worth it. Especially when you can get weapons, armor, supplies and transport for a whole platoon for the cost of one reactor.