There are a number of different rule sets available online, but the most prevalent among them is that you simply ante up cards from your deck, so losing typically weakens your card pool while winning can strengthen it
There is no human handling at the point of sale, no opportunity for pack weighing, and no uncertainty around product condition
Wigglytuff doesn't lay the same claim to the overwhelming popularity of Pokemon like Pikachu and Charizard, but there are still several scintillating cards depicting Wigglytuff enjoying life
Probably more for security purposes
Also, since most of these cards are cheap, other cards like Monastery Mentor or Young Pyromancer have the potential to generate tokens from cheap spells, while others like Shark Typhoon can serve as win conditions on their own
They are approximately 50% larger than standard poker cards, providing greater visibility on the table and making it easier to read from a distance