Pokemon began in 1995, the creation of Satoshi Tajiri, who dreamt up a Nintendo video game series in which fictional creatures are trained by humans to battle each other.
It spawned numerous spin-offs and tie-ins, including films, television shows and an incredibly popular trading card game.
The franchise is one of the most lucrative in the world, with its smartphone game Pokemon Go capturing a new generation of fans last year, while rare versions of the collectible trading cards sell for large amounts of money on eBay and other marketplaces.
The Week
Escape your echo chamber. Get the facts behind the news, plus analysis from multiple perspectives.
SUBSCRIBE & SAVE
Sign up for The Week's Free Newsletters
Join more than 350,000 subscribers and keep yourself informed with a selection of The Week’s most interesting, enlightening and entertaining stories - plus daily puzzles.
Join more than 350,000 subscribers and keep yourself informed with a selection of The Week’s most interesting, enlightening and entertaining stories - plus daily puzzles.
Latest Videos FromThe Week
So how can you tell if your collection is worth something?
How did the collecting phenomenon begin?
Nearly 15 billion Pokemon cards have been produced since they were launched in October 1996, reports the Daily Telegraph.
"For most Brits in their 20s, part of their childhood will most likely have been spent collecting Pokemon cards and pestering parents for packs," says the Daily Mirror, but "since it has been almost 15 years since the huge popularity of Pokemon started to dwindle, you have probably ended up throwing your collection out or losing them".
How can you tell if a Pokemon card is valuable?
It's all about the rarity symbol, says Our Pastimes
"Every Pokemon card has a symbol in the bottom right corner. Common cards have circles, which mean they're not worth anything. Diamond cards are uncommon, and they can go either way in value. Stars are the rarest cards, and some can go for high prices," it says.
Other things to look out for are whether the card is holographic - the Pokemon portrait appears to have foil and shines in the light - or if it has a first edition mark underneath the portrait, both of which greatly increase the card's value.
What are the most expensive Pokemon cards?
The most expensive cards are the extremely rare "Pokemon Illustrator Cards", of which only 39 were made, says Mashable. Last year, a buyer from Hong Kong purchased one for just under £45,000.
Also look out for the "Pre-release Raichu Cards", says CompleteSets: "These cards were printed with the dark black 'Prerelease' text in the corner of the card's character image. Most sites we visited in researching its history set the value at well over $10,000 [£8,000] based on public sales where the card changed hand."
Other rarities include Pokemon cards produced in the early days which, according to a buyer's guide on eBay, are missing the drop shadow on the right and bottom sides of the border around the portraits.
This was a design choice that was quickly changed, so not many shadowless cards were produced. If you have or find one of these, you're in for a big windfall, says Mashable.
