I'm amazed at the number of caravans that we see sporting fancy decals suggesting they can be taken anywhere...

In our travels we are often surprised to see so many new model vans sporting decals suggesting some degree of 'off-road' ability yet clearly they would really struggle once off the bitumen, don't misunderstand me, there are many reputable manufacturers producing exceptional well built caravans today but to be able to claim an 'off-road' status does mean a little more than thin gauge checker-plate aluminum sheeting and a 'treg-style' hitch.
Some, perhaps all, of our mainstream caravan makers turn out different styles of vans to satisfy buyers wishes, usually it is quite clear that one particular caravan might be termed a 'tourer' and it will take you along any bitumen road in the country, next we will have a 'dirt road van' and this one may have extra strength built in and will happily take you beyond the tar but still on formed roads, and finally a true 'Off-road' van and as the name suggests this type of van will go off road, with-in reasonable limits anyway.
It stands to reason that there will be a significant difference between a tourer and an off-road van and this is where the unscrupulous manufacturers (or, more likely the importers) are getting up my nose...a recent visit to a caravan show had me cringing when looking at some of the 'off-road' offerings, and the particularly worrying thing is the 'off-road' prices being asked.
With this in mind I thought I'd raise just a few of the differences one can expect to find when considering purchasing a caravan that, whilst it might not be able to climb Uluru you can reasonably expect it not to fall apart after a few kilometers of corrugations.
The first thing I would really suggest is that you take a good flashlight with you and get into the cupboards, what you would expect to see will be screws and few staples...in some areas such as the ply that covers the areas under the seats you may find staples but not in any structural area...look under the bed, get right down because staples, if any, will be hidden...stick your head in the cupboard under the sink, crane your neck, what holds the kitchen bench to the cupboard frame?..expect not to see staples on anything that is remotely related to off-roading. Note here that chipboard in itself is not necessarily bad, there have been some improvements in recent years  with chipboard construction, I would be more concerned with the way the van is held together, I have seen some shockers.
In my opinion the type of roads a caravan can travel on is more determined by whats under it than any other thing...the following photos illustrate my thoughts here...click on one and use the arrows to view a slide show..