Prodigality may limit capacity to act
The following circumstances, among others, modify or limit capacity to act: age, insanity, imbecility, the state of being a deaf-mute, penalty, prodigality, family relations, alienage, absence, insolvency and trusteeship. The consequences of these circumstances are governed in this Code, other codes, the Rules of Court, and in special laws. Capacity to act is not limited on account of religious belief or political opinion. (Article 39, Civil Code)
"Under our law it may be inferred that the acts of prodigality must show a morbid state of mind and a disposition to spend, waste, and lessen the estate to such an extent as is likely to expose the family to want of support, or to deprive the forced heirs of their undisposable part of the estate." (G.R. No. 445, March 31, 1902) "[U]ndisposable part of the estate" refers to the legitime (the compulsory share of an heir).
According to Albano, a spendthrift is "a person who, by excessive drinking, gambling, idleness, or debauchery of any kind shall so spend, waste or lessen his estate as to expose himself or his family to want or suffering, or expose the town to charge or expense for the support of himself and his family."