Social games aren't dying -- they're changing. Steve Meretzky (Playdom, pictured) and Dave Rohrl (Goko) kicked off their yearly "Social Games Year in Review" session at GDC Online with a mixed bag of facts; on one hand, the top game on Facebook is Zynga's Texas HoldEm Poker, a five-year-old game that, at 6.3m daily active users (DAU), has the lowest DAU for a #1 game on the platform since before FarmVille. Much of the hype in social games has gone instead to mobile games. On the other hand, Facebook's user count continues to climb (most recently surpassing 1 billion users), and social games revenue continues to climb as well, with the Casual Games Association forecasting total revenues hitting $8 billion by 2014. In short, the market is changing rapidly, and devs will have to quickly learn from the last year of changes if they want to stay in the social games arena.

1. Hidden-object games (HOG) are here—and we're still figuring them out

Starting with Playdom's Gardens of Time, we've seen hidden-object games arrive on social platforms with a big splash. "This is the most popular category in the casual downloadable market, but it didn't exist on Facebook until a year and a half ago," said Meretzky. But if Gardens of Time and Zynga's Hidden Chronicles brought the genre to social games, they also may have gotten close to saturating it as well. Meretzky pointed out that Playdom's later HOG release Blackwood and Bell launched with darker, harder hidden-object screens and a more-complete feature set (B&B was built upon the Gardens of Time codebase, which had time-limited chapters, collections, and an upgrade mechanic added to it after launch)—but it hit only 1/5th of Gardens of Time's DAU. "We learned that triple-A is important for social games; doing a hidden-object game and not getting the HOG screens quite right is like building a Porsche and not getting the engine quite right," Meretzky said. Also, genre saturation can happen fast. "In social gaming, where development time is really short, so all the players can quickly fill up the space. It's like that Yogi Berra quote: 'That restaurant is so crowded, nobody goes there anymore.'"

2. Hardcore social games have an audience on Facebook

"Is Playdom's Marvel Avengers Alliance a Facebook game at all? In my opinion, it does an excellent job integrating classic Facebook tropes into a hardcore game," said Rohrl, "We think that virality doesn't work with hardcore gamers, but it can." "It always seems like this is the year hardcore is going to be over, but it seems like there is enough of a constituency there to continue," Rohrl said, "Real innovation can pay here, and core brands -- like Marvel -- can work."

3. Learn from King.com's "Saga" model—but second fiddle is risky

King.com's "Saga" model of building social games—combining simple, addictive mechanics with a linear metagame progression shown on a map—is core to their success (see Bubble Witch Saga, Mahjong Saga). "They keep the metagame framework similar from game to game, so that players that come from one game will know how another works," said Meretzky, "On the strength of their 'Saga' model, they've completely cemented their position as the #2 social gaming company." "The mechanics that worked in the casual downloadable market will probably work in social," he noted, but then he offered a cautionary note: "We've kind of seen this phenomenon before with CrowdStar in 2009-2010, then Wooga in 2010-2011, and this year it's King.com. CrowdStar has completely pivoted out of social gaming, and Wooga is still in it but has yielded their spot to King, so we'll see if this turns into something sustainable."

4. Facebook is opening up new viral channels for game devs.

"Let's talk about Zynga's Bubble Safari," said Rohrl, "It's a bubble game, like about 30% of the games on Facebook. Now, this Zynga game was not the first Facebook hit in its genre...at the end of the day, it's Bubble Witch Saga with a lot of awesome virals." Rohrl pointed out that Bubble Safari demonstrated plenty of virality vectors that previously weren't allowed on Facebook, like a Select All button for messaging Facebook friends, and a "frictionless spam channel" that let you send game requests to friends without asking for permission each time. These vectors led to Bubble Safari hitting #6 in DAU and revenue. "Virals are immensely relevant for your game's growth, and sustaining your player base," Rohrl concluded. "The platform is opening up new channels to make these virals more efficient and effective. Many segments of the audience previously thought to be viral-averse are actually showing a pretty reasonable propensity. So it's worth actually trying it out on your audience to see how they react."

5. Production values are soaring.

Social games production values are skyrocketing, making it harder for new studios to compete as the minimum production value required to attract players increases the barrier to entry. Meretzky's example was Zynga's FarmVille 2: "We've been saying this is a market that is maturing rapidly. Now we can say it's a mature market, and as that happens, the minimum production values are going up. If you were thinking about going into social gaming, it's not newbie-friendly any more. Finally, don't lose the soul. As budget gets bigger and teams get bigger, it's easy to lose track. Make sure to use those resources to benefit, not crush, the soul of the game."

6. Established IPs won't sell a bad game.

The Sims Social and CityVille both hit 10 million peak DAUs at their peak, but SimCity Social—a big-budget social game with an established IP and design elements from both games—peaked at only 1.6 million. "A great brand can't sell a tired game," Rohrl said, "A brand helps you with trial, but not conversation. If it's not well-planned or executed, it's not going to work out." Rohrl pointed to a series of social games that used established IPs with mixed results; Marvel Avengers Alliance did well, as did Zynga Slingo, but other IPs like House M.D. didn't seem to do too well. "It's really important that your game captures the essence of the license," Rohrl said, "SimCity Social lacked the zone management that made SimCity a huge blast to play."

7. Take innovative risks (and learn from them).

Meretzky showed a relatively obscure social game called Triviador, by Hungarian studio THX Games PLC that is something of a mix between Trivial Pursuit and Risk. Triviador's question set requires players to type in numerical answers (years, amounts, and so on) and rewards players according to how close they were to the answer. "Numeric trivia answers are pure genius," Meretzky said, "Normally you know the answer, and the question is boringly easy, or you don't, and it's boringly hard." Devs can learn from what games like Triviador do well, and avoid what they do poorly—for example, Meretzky thinks that combining real-time multiplayer with strangers and trivia can make people feel stupid, which makes the game less popular.

8. Asynchronous games play to social games' strengths.

Rohrl brought up SongPop (FreshPlanet) and Words With Friends (Zynga) as examples of how social games are well-served by asynchronous game design—particularly as social game developers try to move into the mobile games market. "Even though Zynga has achieved the most crushing success with Words With Friends, we are seeing real traction from indies," said Rohrl, "This is a really vibrant category on mobile, and gameplay that works there seems to transplant well from Facebook. Also, it's great for retention."

9. Gambling is big—and could be bigger

"Gambling isn't new to social games, but now the big boys are starting to move in. Case in point: Zynga Slingo," Meretzky said. "Three of the top four games on Facebook right now are gambling games: Texas HoldEm, DoubleDown Casino, and Slotomania. Meretzky contends that this isn't just for the immediate future, but a longer-term play: "This has been a very indie-friendly area of social gaming, but that's changing quickly. They're high 'ARPUed-out' games. People are used to paying for gambling. Of course, it's a play for money today, but it's also a play for money tomorrow—to prepare for a possible future where gambling is legalized in the US."

10. Real-time PvP isn't ideal for social games

Social games built around real-time player vs. player mechanics can build strong communities, but the social platform poses devs major challenges for in both game design and audience. "Synchronous head-to-head games actually build long-lasting, passionate communities," Rohrl said, "But it doesn't align particularly well with the Facebook platform, which is designed to allow you to interact with friends who are not online, and the games are designed to allow you to interact with strangers who are online. Finally, these games can pose major monetization challenges, since your players are often hard to extract revenue from." Gamasutra is at GDC Online in Austin this week. Check out our event page for the latest on-site coverage.