This is a strategic game that also encourages maths, but requires someone to play with. There are thousands of cards to collect and build your Deck from, using a minimum of 40 cards, so even then you have a lot to think about in terms of strategy.
As with all cards, they're damaged easily, though you can buy individual covers for your cards (They come in packs of 50 and there are all kinds of designs available) to protect them.
Fans of the show can imitate some of the strategies they've seen performed by their favourite characters, but some of the strategies are actually illegal, according to the rules.
Just as Pegasus said in the manga, this is a growing game, continuously changing. There are always new cards being brought out, and the rules are constantly being updated.
For example, when I started to collect the cards, Monster Reborn Spell Card was permitted. Now it's a banned card. This doesn't really have to affect you in a friendly match with your friends, but it's best to learn the rules properly if you have plans on entering a tournament.
All in all, it's a fun game. But you're better off going for the later cards, because nowadays the original ones, such as the Kaiba and Yugi Starter Decks, are overpriced, at about 4 times the cost I got them for. If you want value for money, there are packs of 100 cards for around £5.