Ray, excellent observation about what we mean by cheater plugs.

In the context of trying to get more power than 30 amp I consider the dual plug adapters such as the 30 and 20 amp plugs going into a common 50 amp receptacle that will plug into your 50 amp cord is what I consider a cheater.

The intent is to get more power into the coach than just the 30 amp.

The problem I mentioned is that campground almost universally have GFCI 20 amp receptacles and unless the coach has a transfer switch that established a ground before allowing power into the coach it is unlikley the cheater will work.

Other plugs such as a 50 to a 30, or a 50 to a 20, or a 30 to a 20 are not cheaters, but adapters.