Short answer. Only the freeing part has value. Article 932 says a legacy of a thing that already belonged to you when the will was made is ineffective, even if someone else has an interest in it. But where the testator expressly orders the thing freed of an encumbrance, the gift is valid to that extent — you get the discharge.
What the law says
The legacy or devise of a thing which at the time of the execution of the will already belonged to the legatee or devisee shall be ineffective, even though another person may have some interest therein. If the testator expressly orders that the thing be freed from such interest or encumbrance, the legacy or devise shall be valid to that extent.
Civil Code, Article 932 — A Thing Already the Legatee's. Read the full provision →
What Article 932 provides
Article 932 provides that the legacy or devise of a thing which at the time of the execution of the will already belonged to the legatee or devisee shall be ineffective, even though another person may have some interest therein. If the testator expressly orders that the thing be freed from such interest or encumbrance, the legacy or devise shall be valid to that extent. You cannot be given what is already yours. So a bare gift to you of property you owned when the will was signed does nothing — there is nothing to transfer. The article then rescues the one part that can add value: an express order to clear an encumbrance off it.
Why giving you your own thing is empty
A legacy operates by transferring something to the beneficiary. If the thing was already the legatee's when the will was executed, there is no transfer to make, and the gift is ineffective. This holds even though another person may have some interest in it — a mortgagee, a lienholder, a co-owner. Their interest does not change the basic point that the ownership is already yours. The testator's apparent generosity in 'leaving' you your own property is, by itself, an empty gesture in law, however well meant.
The part that does have value: freeing the encumbrance
That 'something more' is an express order to free the thing of the interest or encumbrance on it. Where the testator directs that your property be cleared of, say, a mortgage, the legacy is valid to that extent — meaning the estate must discharge the encumbrance, and the value you receive is exactly that relief. If a mortgage of a certain amount burdens land you already own, and the will orders it freed, the estate pays off the mortgage and you keep the land unencumbered. The gift is worth the burden lifted, not the land, which was yours all along.
Reading a gift of your own property
If a will 'leaves' you something you already own, do not assume it is meaningless, but do not assume it transfers the property either — it cannot. Look instead for an express direction to free it of an interest or encumbrance, because that is the only part capable of benefiting you. If there is such an order, identify the encumbrance and its amount, since that measures what the estate owes you in discharge. If there is not — just a plain gift of your own thing — the clause gives you nothing.