Paragon's itemization system is founded on the purchasing of Attributes to buy Cards and attain Gems. Every Attribute increase costs 1000 gold and gives immediate stats while storing pips that can be traded for Cards when you return to the Fountain.
There are 3 Attributes: Agility, Intellect, and Vitality. Agility will improve the effectiveness of basic attack-based Heroes, Intellect allows ability-focused Hero to use their talents more, and Vitality increases the survivability of any Hero who invests in it.
As you purchase Attributes you will bank what are call "pips". Nearly every Card in the game has an associated pip cost which is noted on the face of the Card. When you have the required pips, you may return to Fountain and place the Card in your Hand. You do not lose pips when you do this! They are stored on the Card itself. If at any time you remove the Card from your Hand the pips are refunded and available to use when selecting another Card from your Deck.
Gems are selected before the match when you create you Deck. Unlike Cards, they are automatically unlocked and give you their effects and stats when you reach their threshold in the given Attribute tree. The Gem thresholds are 1, 7, 13, 19, and 25 pips. Some Gems have stats on them in addition to their effect, this is dictated by the tier of the Gem. Tier 3 and 4 Gems, requiring 13 and 19 pips respectively, each grant an additional 1000 gold worth of a single stat. Tier 5 Gems, requiring 25 pips in a single Attribute, grant 2 separate stat increases valued at 1000 gold each.