Can a Person Sell or Transfer Their Rights Under a Will for a Still-Living Person?

No. Since a will does not take effect until the testator's (i.e. the will's creator) death, a person who has rights under the will technically doesn't own anything until that time. Therefore, if a person tries to sell or transfer their rights under a will for a still-living person, they have nothing to transfer since they haven't received any property yet. Consequently, most courts consider contracts dealing with rights in wills for still-living persons void.

But Couldn't the Contact Still Be Considered Selling or Transferring a Promise?

Yes, but it's a promise in property that may never materialize. Until the testator dies, someone's rights in a will can always be taken away (e.g. if the testator decides to take people off their will or construct a new will altogether). In other words, anyone who tries to sell their rights in a still-living person's will is essentially selling a lottery ticket that may or may not pan out. As a matter of public policy, courts generally want to stay away from these types of "gambling contracts."

So What Happens If a Person Sells Their Rights in a Still-Living Person's Will, and the Testator Dies? Is the Sale Still Considered Void?

Not necessarily. In some states, the sale or transfer of the rights in the will is now considered a valid contract. Since the testator has died, all rights under the will have materialized, and any person expecting to receive property under a will officially has claim to that property. Therefore, anyone who sold their rights under the will is now obligated to transfer whatever property they receive to the rightful buyer.

But Doesn't This Contradict the Rule that Contracts for the Sale of Rights in a Still-Living Person's Will are Void?

No, as there is no longer any uncertainty. As stated above, rights in the will have materialized since the testator has died and the will can no longer be changed. Also, as a matter of public policy, courts want to enforce these types of promises. For example, suppose X sells his rights to a painting under his still-living uncle's will to Y for $500. Now assume that X's uncle has died, and X now legally owns the painting. If the contract between X and Y were considered void, X would have both the painting and the $500, leaving Y with nothing. Therefore, by requiring X to honor the contract, both X and Y end up with what they wanted:  X gets his $500 and Y gets the painting. It is important to note that, like any sale of property, the normal rules of contract law do apply. Therefore, if any of requirements for a valid contract are not met, then the sale will still be considered void.

How Can a Lawyer Help Me?

If you have bought rights to a will that has just taken effect, and the seller refuses to honor the sale contract, you should contact an estate lawyer immediately. A lawyer can inform you about laws in your state dealing with sales of rights in wills, and help get the property you rightfully deserve.