Proper time, an Uncommon card

The card carries these facts from its Wikipedia article.

• The proper time interval between two events on a world line is the change in proper time, which is independent of coordinates, and is a Lorentz scalar.
• The interval is the quantity of interest, since proper time itself is fixed only up to an arbitrary additive constant, namely the setting of the clock at some event along the world line.
• The proper time interval between two events depends not only on the events, but also the world line connecting them, and hence on the motion of the clock between the events.

Rarity in WikiCards follows a year of Wikipedia page views: the most read articles become Epic and Legendary cards. The Proper time article was read about 39,000 times in a year. ATK comes from the length of the article and DEF from its quality, so this card hits with 65 and blocks with 42: each hit it takes is cut by 17 %.

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 Proper time in the power ranking, all domains together.