Has a face value of 3 Marks. Minted by the kingdom of Prussia to commerate the 100 anniversary of the Breslau university. Krause's 34 edition lists it at $18 in fine condition. Yours does seem to have some significant damage, so it may only go for its Bullion value.
Side note: The university in Breslau/Wrocław is actually older than that; it was founded in 1702. (Back then the city was part of Austria-Hungary, later it became Prussian and then German; today it is Polish again.) In 1811 however the Prussian government merged the "old" Breslau university and the one in Frankfurt/Oder, and the coin does indeed commemorate that centennial. Christian
