Short answer. Yes. Article 868 says the nullity of a fideicommissary substitution does not prejudice the institution of the first-designated heir; the void clause is simply treated as not written. The first heir keeps the inheritance outright, freed of the invalid duty to preserve it and pass it on to a second heir.
What the law says
The nullity of the fideicommissary substitution does not prejudice the validity of the institution of the heirs first designated; the fideicommissary clause shall simply be considered as not written.
Civil Code, Article 868 — A Void Substitution Does Not Kill the Institution. Read the full provision →
What Article 868 does
Article 868 provides that the nullity of the fideicommissary substitution does not prejudice the validity of the institution of the heirs first designated; the fideicommissary clause shall simply be considered as not written. A fideicommissary substitution is an arrangement where the first heir is charged to preserve the inheritance and, in time, transmit it to a second heir. When that substitution is void — because it breaks one of the conditions the law imposes on it — the article does not pull the whole gift down with it. It saves the institution of the first heir and deletes only the offending clause.
Why the first heir is not punished for the defect
The reasoning is that the two parts of the gift are separable. The testator did two things: he gave the property to the first heir, and he tried to burden that gift with an obligation to hand it on later. The first act is a perfectly ordinary institution of an heir; only the second, the substitution, is flawed. Article 868 lets the good stand and strikes only the bad, rather than treating the testator's whole intention as spoiled by one invalid feature. The first heir did nothing wrong and loses nothing; he simply takes what was given, without the string attached.
What 'considered as not written' actually means
Treating the clause as not written is a strong remedy. It is not merely unenforceable — it is read out of the will entirely, as though the testator never inserted it. The consequence is that the first heir's ownership is full and unconditional. He is under no duty to preserve the property for anyone, no duty to transmit it on his own death to the intended second heir, and he may deal with it as any owner would. The second heir, whose interest depended entirely on the void substitution, takes nothing under it; the clause that would have benefited him has ceased to exist.
Common reasons such a clause fails
Fideicommissary substitutions are valid only within tight limits, and a clause that oversteps them is the usual reason one is struck. It must not burden the legitime, it cannot go beyond one degree from the first heir, and the first and second heirs must both be living when the testator dies. A substitution that reaches a generation too far, or one imposed on a compulsory heir's reserved share, falls outside what the law allows. If you are the first heir under such a will, the question worth settling is not whether you inherit — you do — but whether any burden on your ownership survives.