This is usually achieved by sending an act so laughably bad that they have no chance of winning.
Heck for most countries, the act can be so bad that they won't even get into the final. The night everyone considers to be Eurovision proper.
(There are a handful of countries that always get into the final and we'll cover who they are and why they get a free pass in another post.)
Why do this?
Mostly it comes down to money.
Ireland is the prime example of this, although it has been known to happen with other coutnries.
As previously stated, Ireland is the most successful country in Eurovision history (something Irish-Americans never seem to be aware of, for some puzzling reason) and the 1990s was their most successful decade with three consequetive victories and another a couple of years later.
The 2000s, however were not kind, and this is largely due to self sabotage.
Ireland is not a rich country. Or at least it didn't used to be, the Celtic Tiger did a lot of work to rapidly improve the economic standing of Ireland in the world and even living standards in Ireland itself.
It wasn't so long ago that a scarily high proportion of people did not have running water in their homes.
To make this all even more depressing is that the Celtic Tiger only kicked in around the time that the Troubles ended. AKA The reason why a gun company throwing a hissy fit over Liam Neeson's ability to seperate the cool fantasy of firing guns at bad guys from the harsh reality that barely restrained gun ownership leads to people dying is so unforgivable.
If you're unaware of what the Troubles were like, and you're not easily thrown into a fit of abject depression at the cruelty and injustice of the world, I'd suggest doing some research on them.
It explains a lot about a lot of things.
So considering this, and considering that the economic crash put Ireland back onto a far more shaky footing financially than it had been the years previous, it was not financially viable for the country to keep hosting it.
Hence the self sabotage.
I mentioned Jedward before as self sabotage, and the performance was pretty dire, but it would be far from fair to call them the worst act Ireland has had to offer.
Heck, giving anyone the title of 'worst act from x country' is a horrid thing to do. Labelling them as self sabotage isn't great either, but come on, I showed you the performance, you saw how bad they were.
Jedward can do a heck of a lot better than that.
Anyway, I can show you a contender for Ireland's worst Eurovision act, and it's way worse than Jedward on just a conceptual level.
Yeah, that's a turkey puppet.
Yeah, the song is called 'Irlande Douze Pointe'.
And yes, it does sound like that.
After some reasearch, this is indeed a song that the people of Ireland voted for in Eurosong 2008.
How did RTE end up putting this song in their competition in the first place?
Easy, that's Dustin the Turkey. He was the star of a kid's programme called The Den from 1989 until 2010. On RTE.
Or cad iontas, I suppose.
I've been watching Eurovision for a long time, and without a doubt, this is the worst Eurovision song I've ever seen.
Worse than Jemini in 2003 and they were actualfax out of tune the entire time.
Dustin didn't make it to the final, unsurprisingly.
Interestingly enough, self sabotage isn't an accusation that is thrown about all that much.
You'd think that any sufficiently bad song would end up with someone going 'yup, Latvia really doesn't want to win this year', but that's not really how it works.
There's a certain type of song that you see on Eurovision and while that would be considered terrible by the standards of the average native English speaker (for want of a better term), in Eurovision it's the bread and butter.
These are the kinds of songs that people watch Eurovision for.
There's a reason that the act below is Tumblr's go to example of Eurovision.
This may be bad, but it's not the kind of bad that's going to attract accusations of self sabotage, because it's Eurovision.
You can barely get more Eurovision than this.
In fact, you're more likely to be accused of self sabotage if you enter a song that's objectively better than those like this one.
Like Denmark's song from last year, which The Guardian certainly didn't rate.
Yeah, I can kind of see where they're coming from.
The accusations can come from within, like I mentioned previously about Eurosong 2015 and Johnny Logan's feelings about the time slot, and the UK's repeated failures.
Of course, there's no punishment for a country self sabotaging, but it is definitely a part of Eurovision history and tradition that it pays to be aware of, especially during the semi-finals.
Speaking of the UK's repeated failures, by the way, the winner will be announced after The Voice this Saturday on the Red Button.