Zynga’s corporate development team has been sniffing out developers of web-based hardcore video games, sources tell Inside Social Games.

Speaking on the condition of anonymity, two persons from separate companies confirm that Zynga’s acquisitions arm is reaching out to small and mid-sized developers with core games already live on open web and other games platforms. We understand “core” here to mean massively multiplayer online games, strategy or card games similar to Magic: The Gathering and possibly first-person shooters. Core games typically enjoy smaller audiences than Zynga’s casual games titles, but reportedly enjoy higher conversion and volume. The biggest player on Facebook in this space is currently Kixeye, with just over 5 million monthly active users and above 1 million daily active users.

Up to now, Zynga’s business has been firmly casual with a flavoring of i-gaming through its casino franchise games. While still reportedly profitable, it may be that the developer is reaching a point of saturation with audiences on Facebook and mobile. Zynga’s games destination site, Zynga.com, also doesn’t seem to be opening up its games to an off-Facebook audience. Our AppData traffic tracking service reports that the Facebook audience on the website numbers 5.2 million MAU and 1 million DAU and the user ticker on the site has reported DAU much above that.

Branching out to core games (and possibly other genres) could be a shot in the arm to Zynga’s growth. The developer has some experience with core games via Empires & Allies, which introduced turn-based unit combat vaguely similar to the combat system in Digital Chocolate’s Army Attack. It’s not clear how successful the experiment was in terms of increasing bookings; audience-wise, the game maxed out its audience within a month of launch at 52.3 million MAU and 7.7 million DAU.

A Zynga spokesperson says the company does not comment on rumor and speculation. The company’s Q2 earnings report drops tomorrow.