James Prescott Joule, an Uncommon card

The card carries these facts from its Wikipedia article.

• Joule studied the nature of heat and discovered its relationship to mechanical work.
• This led to the law of conservation of energy, which in turn led to the development of the first law of thermodynamics.
• The SI unit of energy, the joule, is named after him.

Rarity in WikiCards follows a year of Wikipedia page views: the most read articles become Epic and Legendary cards. The James Prescott Joule article was read about 61,000 times in a year. ATK comes from the length of the article and DEF from its quality, so this card hits with 71 and blocks with 63: each hit it takes is cut by 25 %.

Open packs. Each pack holds five cards drawn from real Wikipedia articles, the rarest last, and the fifth card is always Rare or better. The odds are shown in the game. A free pack arrives every hour and two can wait, and the Coins you win in duels buy more packs.

The cards just above and just below James Prescott Joule in the power ranking, all domains together.