PvP
PvP, short for Player versus Player, is the system in Elements that allows players to challenge each other.
Basics
On the game's main page, there are options for three different types of PvP. Two pair you with random opponents, and the other pairs you with the player of your choice.
Random PvP
PvP 1 matches you with another person who selects PvP 1 around the same time. It only allows un-upgraded cards, and it costs 30 electrum to enter a match. All upgraded cards in your deck are temporarily unupgraded for a PvP 1 match.
PvP 2 works the same as PvP 1, except it has no upgrade restrictions and costs 50 electrum. Collectively, these two can be referred to as Random PvP.
PvP Duel
The third option for PvP is PvP Duel. Upon choosing this, you go to a screen which allows you to type in another player's username. Assuming two players attempt to play each other in this way, they will be connected and battle each other just like a Random PvP match. However, there is no cost or reward for PvP Duel