Universal property, an Uncommon card

The card carries these facts from its Wikipedia article.

• Thus, universal properties can be used for defining some objects independently from the method chosen for constructing them.
• For example, the definitions of the integers from the natural numbers, of the rational numbers from the integers, of the real numbers from the rational numbers, and of polynomial rings from the field of their coefficients can all be done in terms of universal properties.
• In particular, the concept of universal property allows a simple proof that all constructions of real numbers are equivalent: it suffices to prove that they satisfy the same universal property.

Rarity in WikiCards follows a year of Wikipedia page views: the most read articles become Epic and Legendary cards. The Universal property article was read about 31,000 times in a year. ATK comes from the length of the article and DEF from its quality, so this card hits with 67 and blocks with 51: each hit it takes is cut by 20 %.

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 Universal property in the power ranking, all domains together.