Brace yourselves, Survivor fans, because Game Changers might be the most cutthroat season the game has ever seen.

Kicking off on Wednesday with a two-hour premiere that also marks Survivor's 500th episode, the idea behind Game Changers is self-explanatory: Competing on Season 34 will be 20 repeat contestants who have made (or at least demonstrated a willingness to make) huge moves in their previous outings that... well, changed the game.

"We look for players who understand that the simple math of it is that 19 out of 20 people will lose ... [and] who, despite those odds, are still willing to say, 'Give me the ball. I'll shoot right now. I will shoot, and if I miss, I'm out,'" host Jeff Probst tells TVGuide.com. "There's probably no escaping that this is a tougher season, because there are no gimmes. ... The first couple of episodes are so unnerving and uneven. They're not typical. There's a tension to them, because everybody is looking around going, 'Oh my god ... Who do I align with? Who do I try to get out?' ... It did feel very much to me like an all-star vinyl table at poker, where every single person is capable of running the table, and you have to be willing to go all in. And if you're wrong, you're out."

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Per usual, there are a couple of twists thrown in. For starters, a new rule says there will be no re-votes after a tie vote, meaning that players must come to an immediate decision of whom to vote out or face drawing rocks immediately. Heading into his 34th season at the helm, Probst admits: "I've been frustrated with one thing, and that is when tribes split a vote to see if there's an idol, knowing they have enough people that it doesn't cost them anything. The way I look at the show is, every single action should cost you. ... So the idea behind this is, if you want to split the vote, you can. But just know, if there is no idol and there's a tie? You're going to rocks."

There's also a new way of finding the immunity idols - and new locations for the idols - that will likely throw a lot of players for a loop, Probst says. "It's super cool. It's another one of those moments where you're going to go, wow, we've never seen that before," he teases. "There is a common theme now, which is, you're going to have to work to find an idol. Even if you find it, you're going to have to work to get it open. Or if you find it, you're going to have to put it together, [take] some sort of risk that you're doing in public."

But perhaps the biggest twist is just the theme of the season overall, which finds contestants scrambling to find their footing right out of the gate.

"One of the big questions this season is, how do you stand out in a season of 20 standouts? What I saw happening was, early on, if you make a move, you'd better follow through, because somebody else has an arrow pointed at you as well," Probst says. "There are going to be a lot of tribal councils where Survivor fans feel a little bit of a loss - because it's not like a normal season where you may have five favorites. A good 15 of the 20, you're probably going to like a lot, and most of them are going to get voted out."

With that said, here are 10 individual castaways and alliances to keep an eye on.

1. Hali Ford
On the surface, Hali might seem undeserving of the title "Game Changer," but underestimate her at your own peril, Probst cautions. "Hali's one of the most deceptive players ever," he notes. "She bats her eyes and sort of plays as though she doesn't quite get what you're saying, and then thinks about it for a little bit. It's all a sham. Hali's uber smart and is playing you all the time." And she won't hesitate to double-cross her fellow castaways if they're not careful.

2. Tony Vlachos and Sandra Diaz-Twine
Neither Sandra nor Tony knows what it feels like to play Survivor and not walk away with a million bucks. J.T. Thomas is also a previous winner this time around, but Probst believes Tony (the winner of Cagayan) and Sandra (a two-time winner), are the ones to watch.Will the two former champs team up or face off? That's the question heading into Game Changers. "Sandra's never been voted out, and Tony comes on like a freight train," Probst notes. "The question is, how will Tony's game play with 19 others? Could he team up with Sandra and say, 'Look, you and I could run this thing'? Or will Sandra look at Tony and say, 'You're gone'? Or will Tony look at Sandra and say, 'You're first out'?"

3. Cirie Fields and Oscar "Ozzy" Lusth
Game Changers will mark the fourth Survivor outing for Cirie and Ozzy, and they're each hoping this time will be the charm. "Ozzy has a big chip. He's been close and self-sabotaged himself," Probst points out. "Survivor is such a demanding game that you're not coming back for a third or fourth time unless there's something burning in your soul. And it can't just be the money. It goes deeper than that. It's playing this complicated game of human poker and trying to figure out how to out-maneuver everybody so that you can say, 'I did it. I actually did it. I beat all of you.'"

And Cirie and Ozzy come in with an existing relationship from their time together on Micronesia. But how will that play out? "Does Cirie come in and say, 'Let's get rid of him as soon as possible,' or does she go to him and say, 'We either become rivals or we work together'?" Probst wonders. "It's a really fun question to watch them dance around, because there's this cloud hovering over everybody, which is, don't trust anyone."

4. Ciera Eastin
Ciera, who famously voted out her mother Laura on Blood vs. Water, is once again here to play. And, according to Probst, it was her frustration with more hesitant tribe members during her second outing on Cambodia that first planted the seed of a Game Changers season in producers' minds."Ciera is one of the people who begged people to play," Probst says. "That probably put the thought in our head in the first place. What if we had a bunch of people like Ciera, who all said, 'Please play? Vote me out. Just vote somebody out.'"

5. Sierra Dawn Thomas
Probst believes that Sierra didn't get a proper chance to play her game when she appeared on Worlds Apart, which may put her at an advantage. "What I saw was a woman who was playing a game, and never kicked it into the next gear -- but left the game ... with another gear ready to go," the host says. "Sierra comes into the game in fourth gear. She comes in saying, 'I'm picking up right where I left off, and it's going to be, for me, the same game but a very different energy. Because now I'm moving.'"

6. Michaela Bradshaw
A standout from last year's Millennials vs. Gen X season, Michaela was asked to appear on the show again just hours after she was (memorably) voted out from that season and said yes immediately. But on Game Changers, she still struggles with keeping her strategy to herself. "She played the first time as a really young person who's volatile, but so clearly gifted in so many ways. Not just physically, but she had strategy nailed," Probst says. "Her mistake was, she told everybody and they went, 'Oh my God, you're phenomenal. Goodbye.' ... Now, can she mature fast enough to realize, I have to change my game and how I play? I think what you get the chance to see this season is a young woman maybe actually grow up. And we're all rooting for her to do that."

7. Caleb Reynolds
Caleb is another contestant whose inclusion in Game Changers may prompt some head-scratching, after he was medically evacuated on Kaoh Rong. "I was really happy Caleb said yes, because of anybody whose game has been interrupted unfairly, it's him," Probst says. "Here's a guy who was doing everything right. He was literally willing to almost die for his tribe. That is a game changer." This time around, his initial goal is simply to make it past Day 9, but it remains to be seen whether the fact that no one really has a handle on his game play will be an advantage for the Big Brother alum or put a target on his back.

8. Tai Trang
Viewers who know Tai from Kaoh Rong season may be surprised at the Tai 2.0 that we see on the brutal Game Changers."I think Tai is a little bit of a wolf in sheep's clothing," Probst teases. "Tai knows this game. And Tai is really good. ... If anything, I think he probably realized last time, if the criticism was anything about me it was that I was too nice. OK. Screw that. You want me to play? I'll play. I'm still gonna protect the chickens, but I'm gonna play."

9. Brad Culpepper
Brad has an even more personal motivation for performing well on Game Changers than his fellow contestants - one-upping his wife Monica, a two-time player who made it to the final tribal council on Blood vs. Water. "I love having Culpepper back," Probst says about one of his all-time faves. "Monica's had a pretty good track record on Survivor, and now Culpepper has a story, and the story is, 'I have to do as well as my wife did. I've got to, otherwise she gets bragging rights. And for a guy like Brad, who has so much at stake, the thought of getting voted out early is hanging over his head from Day 1."

10. Malcolm Freberg
Perhaps more than any other Game Changer, Malcolm comes in to the season with a chip on his shoulder, having been voted out twice previously on Philippines and Caramoan. "Malcolm has a lot to prove," Probst says. "And I get it. He's got all the skills. He just hasn't closed the deal yet, and I do think he comes into this [thinking], 'This is my season.'"

Survivor: Game Changers premieres Wednesday at 8/7c on CBS. Who are you rooting for?

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