Aims. The paper presents defects in testator's declaration of will that - according to the provisions of Article 945 Par. 1 Item 1 of the Civil Code – result in invalidity of the will.
Review. The defects consist in the testator's state excluding his conscious decision making or discretion of decision and declaration of will, in the result, in particular, of mental illness, "mental retardation" or other; even transient disturbance of psychological functions listed in Article 82 of the Civil Code. Both in the case of an ordinary will and will in a non-standard form, the court instructs an expert psychiatrist to assess whether the testator's condition enabled him/her to make the decision and declare their will consciously and freely or whether this was excluded. Since the Civil Code does not pro vide any intermediate states of the testator, the court expert cannot recognise any limitations of testamentary capacity. In the case of will made in an emergency situation the court may instruct the expert psychiatrist (sometimes psychologists are appointed for the purpose) to assess whether at the time of making the will in a non-standard form the testator was under apprehension about his/her imminent death.
Conclusion. The knowledge of these issues is necessary to avoid errors in court expertises.