Action Master
Action Masters are Transformers that traded in their ability to transform to become stronger, faster, and more alive. As the Autobot/Decepticon war drained more and more of their resources, a new source of fueling, Nucleon, was discovered which would grant Transformers amazing power, but at a cost. To compensate for their lost ability to transform, the Action Masters built transforming partners to aid them in battle.
Fandom criticism
The Action Master toyline, depicting the obvious oxymoron of "Transformers who don't transform," generated much initial ire. This ire was magnified as Action Masters were released in the death throes of the original Transformers toyline, so when Transformers was summarily cancelled in North America, many fans blamed the gimmick for the death of the franchise.
One aspect Action Masters is notable for, however, is the mass reintroduction of "classic" characters. New toys of old characters is not a theme the original toyline visited very often, and so to have a single subline with so many recurring favorites was, at the time, a novelty.
As with many other changes to the Transformers brand, initial hostility towards Action Masters from the fandom eventually became less intense, and diversified into a broad range of opinion. Many of the most in-demand vintage Transformer toys are Action Masters, and new characters from this subgroup are still harkened back to in newer toylines. For example, Axer shows up in the Robots in Disguise toyline, Armada Overload has design elements based on Roll-Out, and Cybertron Smokescreen's colors are a partial homage to Rad.
