So I took this internet test (yeah, I know) regarding the english vocabulary. I'm curious how the people at mmo-c perform here. Test Yours!
http://www.arealme.com/vocabulary-size-test/en/
As a non-native speaker the results were way over my expectations. To be fair I mostly used the method of elimination when the words became more rare and it's a test on the web so the results may very well be off.