I consider using a RTW ticket but I wonder what happens if I get denied an entry for a country in the midst of the whole itinerary.

Usually these programs set a rule such that once the itinerary is decided or once the trip started, you cannot change the route, yet you can change the date for free.

In this case, if you are denied an entry for a country, will you get deported to the departure country or to the next (or another) country by changing the date of the next flight at the border control? And is the subsequent itinerary still valid or does the one denial make all of the subsequent flights invalid?

If the specific program is required, it is the Star Alliance RTW redeemed on the ANA mileage program. But I would like to know a general answer, if possible.