Paragon is an upcoming third person action MOBA developed by Epic Games and designed from the ground up to follow Dota 2's free to play model. In other words, all of the heroes are free and the cosmetics can be either bought with cash or simply earned through in-game means.
While Paragon might be completely free its early access beta is not, so if you want to be among the first to get in on the action you'll have to grab one of the three Packs filled with skins and other assorted trinkets. Here's how it works:
The cheapest way to enter the early access beta is by purchasing the Founder's Pack which will set you back $20 and give access to various in-game skins, boosts and other cosmetic effects.
On the other hand, if you feel like spending increasingly silly amounts of money you can go for either the Challenger Pack ($60) or the Master Pack ($100) which bring with them a huge amount of skins, unlockable items, boosts, exclusive cosmetics and finally a Founder's Pack to give to a friend. The full details on the contents of each pack should be arriving in a couple of days.
No one expects the guy called Twinblade to whip out two rifles
Before you take the plunge do be aware that Paragon is currently unfinished and as such there are missing features, placeholder content and plenty of bugs that await future squashing. On the positive, side Epic Games promises to release a new hero every three weeks as well as host numerous community events which might come with some cool rewards.
Paragon is entering early access, and not the Steam kind despite the same name, on March 18th. I'm not sure why would you given that there is no benefit but you will be able to preorder the Founder's Packs starting on March 14th.
Finally, if paying for a beta test simply isn't your thing an open, and most importantly free, beta will begin in the summer of 2016.