Short answer. Yes. Mixed succession — succession effected partly by will and partly by operation of law — isn't limited to wills that deliberately leave some property undisposed. If a court voids part of a will's dispositions, the affected property passes by intestate succession while the valid parts of the will still take effect, producing exactly this mixed result.
What the law says
Mixed succession is that effected partly by will and partly by operation of law.
Civil Code, Article 780 — Mixed Succession. Read the full provision →
Two different roads into mixed succession
Mixed succession most commonly happens when a testator's will simply does not dispose of the whole estate — naming an heir for certain property while leaving the rest untouched. But the same result can happen involuntarily: if a court later declares part of a will's dispositions invalid, the property those dispositions covered is treated as though the will never addressed it. Either way, the estate ends up governed by two systems at once, testamentary succession for what the will validly covers and intestate succession for the rest, regardless of whether the gap was the testator's choice or a judge's ruling.
The valid dispositions still stand
Voiding one part of a will does not automatically bring the whole document down. Under the related rule on severability, dispositions that are legally invalid are treated separately from the rest of the will, so the heirs and legacies the testator validly named still take effect as written. Only the specific property tied to the invalid clause falls outside the will's operation and needs another distribution rule to govern it, while everything else the testator arranged proceeds exactly as written.
How the orphaned portion is distributed
The property left uncovered — whether by deliberate omission or by a court's invalidation — passes according to the default rules of intestate succession, as if the deceased had died without a will as to that portion. It goes to the legal heirs in the order the law fixes: children and other descendants first, then ascendants, the surviving spouse, and collateral relatives, following the same priority that governs a wholly intestate estate. The share each heir receives from that portion is computed under the ordinary intestate rules, not by anything the will says.
What this means for the heirs
For the family, mixed succession can mean receiving property two different ways within a single estate — some of it under the terms the testator chose, and some of it under the shares the law assigns by default. Both are enforceable simultaneously, and an heir's total inheritance may end up being the sum of what the will gives plus whatever share intestate succession separately allocates to that same relative, which can make settling the estate more complicated than either mode of succession alone.
Related provisions
- Civil Code, Article 780 — Mixed Succession
- Civil Code, Article 779 — Testamentary Succession
- Civil Code, Article 792 — Invalid Dispositions Are Severable