“The ‘Arm Chair Rule’ was originally propounded in Boyes v. Cook ((1880) 14 Ch.D 53). The Rule reads thus:

“Armchair Rule” - Although, a will always speaks from the date of the death of the testator, in construing the will, the court of construction should determine the facts and circumstances respecting the testator’s property and his family and other persons and things as at the date of the will, in order to give effect to the words used in the will when the meaning and applications of his words cannot be ascertained without taking evidence of such facts and circumstances. For this purpose, evidence is received to enable the court to ascertain all the persons and facts known to the testator when he made the will. The court, it has been said, puts itself into the testator’s armchair.”

Example: A testator makes a bequest to “my nephew and nieces”. The testator had no nephews and nieces at the date of the will or at the time of his death, but there were nephews and nieces of his wife. Evidence will be admissible to show that the words referred to the nephews and nieces of the testator’s wife.