Property classification and succession law intersect in a way that often surprises families with “mixed” parentage (children from different relationships). In the Philippines, two bodies of rules drive outcomes:

Property relations of spouses (what belongs to whom during marriage and what forms part of the estate at death), mainly under the Family Code of the Philippines; and
Succession rules (who inherits, how much, and under what barriers), mainly under the Civil Code of the Philippines.

This article explains (A) inherited vs conjugal/community property, (B) how estates are formed and liquidated, and (C) intestate and legitime rules that control succession rights between half-siblings—including the half-blood rule, the “iron curtain” rule, and special doctrines like reservation troncal.

1) The two questions you must separate

Question 1: “Is this asset part of the deceased’s estate?”

Not everything “in the household” becomes inheritable at death. If the deceased was married under a property regime (Absolute Community or Conjugal Partnership), the law first determines:

which assets belong exclusively to the deceased,
which belong to the community/conjugal partnership, and
which belong exclusively to the surviving spouse.

Only the deceased’s net share (after liquidation and payment of obligations) is distributed to heirs.

Question 2: “Among the heirs, how will shares be computed?”

Once the net estate is identified, succession rules determine whether half-siblings inherit at all and, if yes, in what proportion.

2) “Inherited property” in a marriage: usually exclusive, not conjugal/community

A common misconception is that marriage automatically makes everything “conjugal.” Under both major regimes in the Family Code of the Philippines, property acquired by gratuitous title—inheritance or donation—generally stays exclusive to the spouse who received it, subject to important nuances.

A. Absolute Community of Property (ACP)

Default regime for marriages celebrated after the Family Code took effect, unless there is a valid marriage settlement choosing another regime.

Under ACP:

Community property (generally): property owned by either spouse at the time of marriage and acquired thereafter becomes community.
But exclusions are crucial: property acquired during the marriage by gratuitous title (inheritance/donation) is excluded from the community for the donee/heir spouse, unless the donor/testator expressly provides it will form part of the community.

Key succession impact: If a spouse inherited land during the marriage, that land is typically exclusive. When that spouse dies, that inherited land is included in the deceased’s estate in full (subject to estate obligations), not “half” to the surviving spouse by property regime—though the surviving spouse may still inherit from it as an heir.

B. Conjugal Partnership of Gains (CPG)

Often applies where spouses validly agreed to it in a marriage settlement (or for certain older marriages depending on transitional rules).

Under CPG:

Conjugal property: generally the fruits, income, and properties acquired for value during marriage.
Exclusive property includes: property brought into marriage; property acquired during marriage by inheritance or donation; and other exclusive classifications.

Key succession impact: Inherited property remains exclusive, but fruits/income of exclusive property during marriage often become conjugal (e.g., rentals from inherited land, unless otherwise qualified by law and facts).

3) Why this matters to half-siblings: what can be inherited and from whom?

Half-siblings are typically competing claimants in either of these situations:

A parent dies leaving children from different relationships (half-siblings to each other).
One sibling dies unmarried/childless (or otherwise without preferred heirs), and siblings/half-siblings claim by intestacy.

Property classification affects Situation 1 primarily (what makes up the parent’s estate and what the surviving spouse gets before children inherit). Succession rules among half-siblings become decisive in Situation 2 and in special doctrines like reservation troncal.

4) Building the estate: liquidation comes first

When a married person dies, the proper sequence is typically:

Inventory of assets and liabilities.
Determine property regime and classify each asset:
- exclusive of the deceased,
- community/conjugal,
- exclusive of the surviving spouse.
Pay obligations (including those chargeable to the community/conjugal partnership and to the estate).
Liquidate the community/conjugal partnership:
- The surviving spouse receives their share by property regime (not by inheritance).
- The deceased’s share (often ½ of net community/conjugal) becomes part of the estate.
Add the deceased’s exclusive properties to the estate.
Distribute the net estate to heirs (testate or intestate, subject to legitimes).

Takeaway: Half-siblings can only inherit from the deceased’s estate, not from the surviving spouse’s exclusive share.

5) Children of different unions inheriting from a common parent (parent dies)

A. As a rule, a parent’s children inherit from that parent—regardless of “which relationship”

If the deceased parent is the common parent, the children (whether from a prior marriage, later marriage, or nonmarital relationship) may be heirs—but their status (legitimate vs illegitimate vs adopted) changes the computation, and the surviving spouse’s presence changes the partition.

B. Legitimes and compulsory heirs (why “you can’t just give it all to one side”)

Philippine succession law protects compulsory heirs through legitimes—a portion of the estate reserved by law.

Common compulsory heirs include:

legitimate children and descendants,
legitimate parents and ascendants (if no children),
surviving spouse,
acknowledged illegitimate children (recognized under law).

Practical effect: Even with a will, the parent generally cannot disinherit children without a legally recognized cause and proper formality; the legitime must still be satisfied.

C. Surviving spouse + children from different relationships: estate division depends on the children’s legitimacy

High-level rules (simplified):

If there are legitimate children, they generally inherit in equal shares, and the surviving spouse’s legitime typically equals the share of one legitimate child.
Illegitimate children inherit from the parent but usually at a reduced proportion compared with legitimate children, and other restrictions can apply in more complex family structures.

This is where many half-sibling disputes arise: the fight is not only over “whose child” but over legal status, recognition, and proofs (birth record, acknowledgment, legitimacy, adoption, etc.).

6) Half-siblings inheriting from each other (sibling dies): the half-blood rule

When a person dies without descendants, and depending on the presence/absence of ascendants and a spouse, the law may call brothers and sisters (and their children by representation) as intestate heirs.

A. Full-blood vs half-blood: not always equal

In intestate succession among legitimate siblings, the Civil Code provides a specific rule:

A half-blood sibling (sharing only one parent with the deceased) generally receives half the share of a full-blood sibling, when they inherit together in the same class.

Example (conceptual):

Deceased has no children, no parents, no spouse.
Surviving siblings: 1 full sibling (F) and 1 half sibling (H).
The estate is divided into “units”: F counts as 2 units, H counts as 1 unit → total 3 units.
- F gets 2/3; H gets 1/3.

B. Representation in the collateral line

Children of brothers/sisters can inherit by representation if their parent-sibling would have inherited but predeceased the decedent. This can extend the contest to nephews/nieces from different sides.

7) The “iron curtain” rule: legitimate and illegitimate relatives generally do not inherit from each other collaterally

One of the most case-dispositive rules in half-sibling disputes is Civil Code Article 992 (commonly called the iron curtain rule):

Illegitimate children cannot inherit by intestacy from the legitimate relatives of their father or mother, and vice versa.

Why it matters for half-siblings

Half-siblings may share a parent, but if one is legitimate and the other is illegitimate, they fall on opposite sides of Article 992 for collateral succession.

Typical result in many intestate sibling-to-sibling scenarios:

If the decedent is legitimate, an illegitimate half-sibling is generally barred from inheriting as a collateral heir.
If the decedent is illegitimate, a legitimate half-sibling (as a legitimate relative of the common parent) is generally barred.

This rule often overrides the half-blood fraction issue entirely—because the barred half-sibling inherits nothing by intestacy in that route.

Important nuance: Article 992 is about intestate succession and about inheritance between illegitimate persons and legitimate relatives. It does not erase a child’s right to inherit from the parent directly (an illegitimate child can inherit from the parent), but it blocks crossing into the parent’s legitimate family line by intestacy.

8) Inherited property that “wants to go back”: reservation troncal (can favor half-siblings)

Beyond the usual intestate order, Philippine law recognizes reservation troncal (Civil Code Article 891), a special rule that can affect property that:

Came to a person (the “propositus”) by gratuitous title from an ascendant or from a brother/sister (the “line of origin”), and
The propositus later dies without descendants, and
The property is now going to an ascendant (the “reservista”) by operation of law.

In that situation, the ascendant who receives the property may be obliged to reserve it for certain relatives within the third degree from the propositus belonging to the line where the property came from (the “reservatarios”).

How this brings half-siblings into play

If the property originated from the mother’s line, then the reservatarios are relatives within the required degree in the maternal line—which can include maternal half-siblings (sharing the same mother) if they are within the qualifying degree and otherwise legally capable.

This doctrine can sharply change outcomes where:

A child inherits property from one side (e.g., maternal grandparents → mother → child), then dies without descendants, and the surviving parent from the other side receives it—triggering a duty to reserve for the property’s originating family line.

Reservation troncal is technical and fact-sensitive (origin of property, degrees, identities of parties, and sequence of deaths matter), but it is a recurring reason why “inherited property” behaves differently from conjugal/community acquisitions in family disputes.

9) Step-by-step framework for analyzing a half-sibling succession dispute

Step 1: Identify the decedent and the relationship map

Who died?
Who are the claimants (full siblings, half siblings, spouse, children, parents)?
Determine each claimant’s status: legitimate, illegitimate, adopted, etc.

Step 2: Determine if there is a will (testate vs intestate)

If there is a will: check formal validity and whether legitimes of compulsory heirs are preserved.
If none or ineffective: intestate rules control.

Step 3: Classify each asset (exclusive vs community/conjugal)

For each asset, ask:

Was it acquired before marriage?
Was it acquired during marriage for value?
Was it inherited/donated (gratuitous title)?
Were there improvements paid from community/conjugal funds (possible reimbursement issues)?
Are we dealing with fruits/income generated during marriage?

Step 4: Liquidate the property regime (if married)

Pay obligations.
Allocate the surviving spouse’s property-regime share.
Determine the decedent’s net estate.

Step 5: Apply succession rules in the correct order

Do children/descendants exist? If yes, siblings usually do not inherit.
If no descendants, do ascendants exist? spouse?
If siblings are called:
- Apply the half-blood rule if applicable,
- Apply representation rules for nephews/nieces,
- Check Article 992 barriers if legitimacy differs.

Step 6: Check for special doctrines

Reservation troncal (property’s line of origin and sequence of deaths).
Potential exclusions or disqualifications (e.g., unworthiness).
Settlement issues (advancements/collation concepts may matter in some partitions).

10) Common fact patterns and what usually happens

Pattern A: Parent dies; children from two relationships fight over “inherited land”

If the land was inherited by the parent: it is typically the parent’s exclusive property (not conjugal/community), so it goes into the parent’s estate.
Children of the parent inherit from the parent (subject to legitimes and spouse’s share).
The surviving spouse does not automatically own half of that inherited land by property regime, but may inherit a share as spouse-heir depending on the family constellation and legitimes.

Pattern B: Half-siblings inherit from a sibling who dies single/childless

If both are legitimate: half-blood sibling often receives half of a full-blood sibling’s share.
If legitimacy differs between them: Article 992 can bar the inheritance entirely, depending on who is legitimate/illegitimate and the collateral relationship invoked.

Pattern C: Property inherited from one side ends up temporarily with the other parent when the child dies

Reservation troncal may require the receiving ascendant to reserve the property for relatives within the proper degree in the property’s line of origin, which can include half-siblings on that side.

11) Practical notes that decide cases (even when the law is clear)

Status and proof are everything: Birth records, acknowledgment, proof of filiation, and adoption documents often decide who is even an heir.
Titles do not always reflect true ownership: “In whose name” the property is titled is not always the end; property regime and source of funds matter.
Settlement timing matters: Death order, remarriage timing, and whether property was partitioned during life can affect what remains in the estate.
Many disputes are really liquidation disputes: Parties argue “inheritance shares,” but the bigger money is often in whether an asset is exclusive vs community/conjugal, and in reimbursements for improvements, taxes, and expenses.

12) Core takeaways

Inherited property (gratuitous acquisitions) is usually exclusive to the spouse who received it, meaning it generally enters that spouse’s estate in full upon death (subject to debts and other rules), rather than being split by property regime first.
Conjugal/community property must be liquidated first, and only the deceased’s net share is inherited.
Half-siblings can inherit from each other by intestacy only when siblings are called, and then:
- Half-blood siblings generally receive a reduced share compared with full-blood siblings (in legitimate sibling contexts); and
- Article 992 can bar inheritance altogether when the relationship crosses between illegitimate persons and legitimate relatives in collateral succession.
Reservation troncal can redirect inherited property back toward the originating family line, sometimes benefiting half-siblings on that side.