An Englishman, an Irishman and a Scotsman" is the opening line of a category of joke popular in Ireland and the United Kingdom. The nationalities involved may vary, though they are usually restricted to those within Ireland and the UK, and the number of people involved is usually three or sometimes four. In Ireland, the characters are sometimes called "Paddy Irishman, Paddy Englishman, and Paddy Scotsman". Depending on who is telling the joke, one nationality fares well and the other nationalities fare poorly according to national stereotypes. For example in England the punchline is usually based around the Irishman being stupid, the Scotsman being mean or frugal, and the Englishman being posh or a snob but ultimately not the butt of the joke, whereas in Scotland and Ireland, the Englishman will typically be the butt of the joke. Sometimes, when the joke requires four people, a Welshman is brought into the joke.
If we are to have a debate about stereotyping people it is perhaps best not to be in jokes topics.