Player-versus-player (PvP) combat is a pending feature for Final Fantasy 14, and one that director Naoki Yoshida sees as a necessary component for an MMORPG. When it is implemented, though, Yoshida wants to make sure it doesn't put off newcomers to the genre.
Yoshida told the Japanese magazine Famitsu (via Polygon) that openly killing players is "not a match" for the franchise. "If you don't know MMOs and you're playing this because it's the new Final Fantasy, I think it'd be a big shock if some other player started attacking you right at the start. So instead of that, the PvP here is a competition between players a way to better themselves, and its essence is different from PKing (player-killing). The fact that the two concepts get conflated with each other indicates, I think, that MMOs and PvP combat still have a ways to go in becoming mainstream."
So if it's antithetical to the franchise, why include it at all? That comes down to personal preference and business considerations, says Yoshida. "An MMORPG needs some kind of consumer activity for the economy to work, and PvP is a great vehicle for that. We're implementing it in part because I personally like PvP, but also because it's indispensable for worldwide deployment. There's never been a really successful MMORPG without PvP."