An illegitimate child is a compulsory heir in the direct line and his omission from the will leads to the conclusion of his preterition.

Under the Civil Code, the preterition of a compulsory heir in the direct line shall annul the institution of heirs, but the devises and legacies shall remain valid insofar as the legitimes are not impaired. Consequently, if a will does not institute any devisees or legatees, the preterition of a compulsory heir in the direct line will result in total intestacy. An illegitimate child is a compulsory heir in the direct line and his omission from the will leads to the conclusion of his preterition. (G.R. No. 198994, February 03, 2016)