As has been said, there are many variations and you should check the owner's manuals for the vehicles you're interested in (under "recreational towing" or similar headings) for the best information.
Very generally speaking however...
- Most two-wheel-drive manual transmission vehicles can be towed four down fairly easily.
- Many automatic transmission two wheel drive vehicles cannot be towed four down, but some can.
- Most four wheel drive vehicles with a transfer case that can be put into neutral can be towed four down (regardless of automatic vs. manual transmission.
- Most AWD and four wheel drive vehicles without a transfer case cannot be towed four down.
- Essentially all front wheel drive vehicles can be towed using a dolly.
- AWD and (I think) four wheel drive vehicles usually cannot be towed using a dolly.
- Any vehicle can be towed on a trailer.