You can add up to four copies of the same card to your deck, which is a rule commonly found in every trading card game
That's pretty straightforward - a spell that has that colour or an ability that comes from that permanent type can't target the permanent with conditional Hexproof
It might result in zero cards or, if you're lucky, it could be ten
Planar Chaos sealed product is quite expensive, mostly because of how scarce it is
This simple step blocks out dust, prevents humidity from warping foils, and completely shields your cards from accidental spills
I weighed a few standard size Pokmon TCG cards of different types and rarities from the Crown Zenith set, and (based on this small sample), the more desirable holo and art cards do weigh more than a normal common card