If you refer to the 1920 British Shilling, it is not rare.
Eric Shilling was born in 1920.
It would be rare, but not very rare. Lots of people would still have them. The Eireann 1931 "Proof" Shilling is quite rare.
The 1923 British Shilling is made from 50% silver, 40% copper and 10% nickel, as are all British Shilling coins minted from 1920 to 1946 inclusive. Assuming that they are not too badly worn, the 1920 to 1936 British Shilling weighs 5.65 grams.
Rare Bird - 1920 was released on: USA: October 1920
Most British One Shilling coins from the past 100 years would not be considered rare. For more detail, you would need to provide the date on the coin.
Rare Bits - 1920 was released on: USA: 4 April 1920
The cast of Rare Bird - 1920 includes: Monty Banks
All 20th Century British Shillings were 23.5 mm in diameter.
One Shilling GBP in 1920 had the purchasing power of about £1.34 GBP today. NOTE - This historical conversion is the result of many calculations and considerations by a purpose designed program for which I can take no credit. The resulting answer should only be regarded as an approximation.
The British Shilling has never been made from gold, and has always been made from silver. From 1920 onwards, the Shilling and all other British silver coins, were debased from Sterling silver (92.5%) to 50% silver.
A schilling is a denomination of Austria, but there was no 1920 Schilling. There was, however, a 1920 Shilling made in the United Kingdom, Australia, and British West Africa. Which country's coin were you interested in?
The cast of Rare Bits - 1920 includes: Carter DeHaven Flora Parker DeHaven