The Essence Orbs are a promotional set that consists of 12 cards. This set was announced as a promotion celebrating the First Year Anniversary of Steemmonsters or what we now call Splinterlands. Card's Rarities are distributed in 3 Legendary, 2 Epic, 3 Rare, and 4 Common Cards. All of them are playable in the Wild Format. 200,000 Essence Orb booster packs were created and can only be obtained through secondary markets like hive engine, tribaldex, or via P2P trade with other players.
The following cards are discoverable in Essence Orbs, additional info about opening rates based can be found in this article.
Single cards can be rented or bought in the In-game Market using in-game currencies such as Credits or Dark Energy Crystals (DEC).