Dark and Darker - Three Loading Screen Artworks That Show Different Actions In-Game
Now, with the general concepts understood, where do beginner Dark and Darker players go to gain EXP? Well, there are quite a few ways to go about this. 

The most obvious method is to Dark And Darker Gold get into the dungeon and kill NPC enemies or other players. But, there are a lot of other actions that grant EXP besides this, such as: Going deeper into the Dungeon through a Red Portal. Defeating the boss at the end of the Red Portal floor.

All of these actions grant EXP, and this likely clears up some questions players might have had about why someone in their party was leveling faster than they were. Dark and Darker - Artwork Of A Party Beginning To Descend Into The Dungeon

Again, there aren't really any numbers out yet for what action in DaD gives the most EXP, especially since this will all likely change between this alpha and the full release. But, players have noticed that certain actions cause their EXP bar to jump pretty noticeably, and these are:

Now, there are other methods of getting a lot of EXP all at once, such as getting a bunch of PvE or PvP kills in a single game or escaping with an inventory full of loot, but the methods above are the singular actions that seem to grant the most overall.

And lastly, let's clear up buy Dark And Darker Gold a few things about leveling or gaining EXP in Dark and Darker that players seem to be confused about: Escaping the Dungeon through a Blue Portal. EXP is (sadly) not currently shared between players in a party for kills (both PvE and PvP).