Say there is a patent out there for something, say a fork and I improve on the design in some fundamental way even though the core of the object is still fork like, do I still have to get permission/pay royalties?
A patent grants you a negative right. That is, it gives you the ability to stop other people from doing something, not to do it yourself.
There are a few times when that's relevant, like if you invent a new way of unlocking car doors, you aren't then allowed to steal cars, or as in your case, if you invent something that improves on something else, you aren't allowed to produce that invention.
The classic example here is a chair. Say I file a patent for,
A wooden structure with four legs and a seat.
You look at that awesome invention, and you say you can improve on it, so you file a patent for,
A wooden structure with four legs and a seat, and a cushion.
In order to practice your invention, you need to get permission from me. In fact, unless you modified your invention to use only three legs, you could never, within the life of my patent, produce that invention without my permission.
But all would not be lost for you, as I'd never be allowed to put cushions on any of my chairs without your permission.
A somewhat common practice in cases like this is referred to as cross-licensing, wherein we agree that you can make chairs if I can put cushions on mine. We're basically trading rights on each other's patents. Of course, if I decided that cushions aren't important and rockers are really where it's at, you'd be somewhat out of luck.
Clearly there are an infinite number of combinations here for how such an agreement could go, and this is just an example. I could add a clause to say you're only allowed to produce chairs with cushions, or that you have to pay me $5 for every one you produce in addition to giving me permission to use your patent, or you may license the patent to me in a profit-sharing deal and I might not give you the ability to produce the chair at all.
But yes, royalties do have to be agreed, and a patent is a patent, no matter what it's a prerequisite to. But those royalties aren't always paid in the form of cash.
The answer to your question is no (for permission) and no (for paying royalties), explained as follows:
You do not need permission since there is no law that prevents the practice of the patent. A patent is a right granted by the government to a person or legal entity such as a corporation. The patent provides the patent owner the ‘right to exclude’ others from making, using or selling the invention claimed in the patent. As the sole source of the patented invention, owners are granted a time limited right to exclude competitors from the marketplace.
The patent ‘claims’ define what the patents cover and what will require royalties (in order to ‘make, use or sell’). The claims are the most important part of a patent. A common misunderstanding is that the claims describe the invention, they do not. Rather they define the literal boundary of the patent owner's right to exclude. Each and every limitation or claim element must be identified - a doctrine known as the all-elements rule. In other words your improvement would add new claim elements to the ‘core of the object’ or known state of the art. Hence you would not be infringing nor required to pay royalties. In patent law “the name of the game is the claim”. Additional information and a useful tool for extracting claim elements can be found at Pelent.com