It's a great way to add some narrative to the game, unlike many other MMORPGs which tend to feel rather aimless.
One of the most popular free MMORPGs is Maplestory.
The gaming experience is much more casual than other MMORPGs, as each dungeon only takes a few minutes to complete.
Massive multiplayer online role-playing games (MMORPGs) are increasingly popular there and most of the top sellers have player kills as a key component of their gameplay.
Since the sudden rise of popularity in MMORPGs (Massive Multiplayer Online Role Playing Games), a lot of online RPGs have jumped to the MMORPG genre, so I'll be referring to them as such.