Short answer. Yes, when a will institutes brothers and sisters without specifying different amounts. Under Article 848, if the testator has both full-blood and half-blood siblings and leaves them the estate without distinguishing between them, all are treated equally and divide the inheritance in equal shares — unless the will itself indicates a different intention.
What the law says
If the testator should institute his brothers and sisters, and he has some of full blood and others of half blood, the inheritance shall be distributed equally unless a different intention appears.
Civil Code, Article 848 — Full-Blood and Half-Blood Siblings. Read the full provision →
The rule of equal distribution under a will
Article 848 applies specifically in testate succession — that is, when there is a will. When a testator institutes brothers and sisters as heirs without specifying who gets more or less, and the group includes both full-blood siblings (sharing both father and mother) and half-blood siblings (sharing only one parent), the default rule is equal distribution. The testator's failure to draw a distinction is treated as an instruction to divide equally, not as an oversight that imports the intestate rule.
How this differs from intestate succession
It is important to note that this is a rule specific to wills. In intestate succession — where there is no will — the Civil Code provides that full-blood siblings receive double the share of half-blood siblings. That differential does not automatically carry over into a will that simply names all siblings without qualification. Article 848 creates a separate rule for wills: when the testator chose to include all of them without specifying amounts, they are presumed to have intended equal shares.
The escape clause: a different intention
Article 848 allows one exception: unless a different intention appears. A testator may expressly provide that full-blood siblings should receive a larger or smaller share than half-blood ones, or vice versa. This intention does not have to follow any particular form, but it must appear from the will itself — from its language, the context of the bequests, or how the rest of the estate is distributed. A vague or ambiguous provision would likely be interpreted under the default equal-distribution rule rather than presuming the testator intended inequality.
What this means for your situation
If your father's will names all his siblings as heirs without specifying different shares, Article 848 means each sibling — full-blood or half-blood — takes an equal portion. If the will does distinguish between them, that expressed intention controls. Either way, what matters is what the will actually says. If the will's language on this point is unclear or disputed among the heirs, the proper venue to resolve it is through the settlement proceedings, where the court can determine the testator's actual intention from the document as a whole.