The content of the strip varied wildly over the years. Some strips were standalone such as the three "Transformers That Didn't Make The Grade" strips which showed Transformers with odd or useless alt-modes such as a fridge or a toilet. A few issues were even used to explain changes elsewhere in the comic, such as Grimlock replacing Soundwave on the letters page or Dreadwind succeeding Grimlock.
Most of the strips however focused on the attempts of an alien King and his chief inventor to invade the Earth using a series of frequently ridiculous robots.
The strip was eventually replaced by "Combat Colin" (also by Stringer) when the Transformers and Action Force comics merged. Issue #200 contained a special joint Combat Colin & Robo-Capers strip in which the King was defeated by Combat Colin and decided to give up attempting to conquer Earth forever. This was the very last Robo-Capers story.