Fifa isn't really a game, goes the perennial message from its creators – it's a continually evolving simulation. Every year, David Rutter, the producer of the series since 2007, has to sit in demo rooms around the world and explain to groups of skeptical journalists what this means.

Fifa 13 doesn't merely refresh Fifa 12 with new players and modes; it's the latest instalment in an obsessive odyssey towards realism. We might not all buy the message, but that's the heart of it. They do love football at EA's sporty Vancouver campus and they're determined to do it justice.

That doesn't always mean a total rewrite of the entire engine, either. The through line of Fifa 13 seems to be refinement.

"Last year was about lots of new technology," says Rutter. "The player impact engine did a good job of updating the fluidity and dynamics of the game - it introduced all these amazing animations, some of which were quite humorous, but on the most part added a sense of continuity. However, they didn't really change the game so much. This year we wanted to take the technological additions and build true game-changing features on top of them."

For attacking teams this is going to mean much more cohesive and expressive behaviour from AI players. "We're doing a lot of work with off the ball runs," says Rutter. "Being able to stay onside better, creating a feeling of the team as a whole attacking with you."

This should put an end to players running in and out of offside positions, blindly prompted by the movements of their team-mates – instead, they should decide where they want to go, and then subtly adjust their direction, shape and pacing depending on the defensive line. "Think pathfinding," says Rutter, "but significantly more committed, dynamic and aggressive."

Rutter also talks about the reactive behaviour of top players – the way Van Persie will realise he's in a poor position, then duck out to forge some space for himself. "Our players will now do that too," he says. "Players will bend their runs wide to allow the ball to be played in behind them.

"Or, if they have nowhere to go, they'll run slightly away from the goal to open up space. They'll also whip around defenders to stay on their run – they're much more decisive."

During my hands-on demo, I saw a little of this happening, especially with computer-controlled players responding much earlier to my attacks. When you go forward, they'll make themselves available even when they're probably a couple of passes away from the ball. Although Fifa players have always stuck a hand up to request the ball, they do seem to be doing it a lot earlier in Fifa 13, gaining a few yards on defenders since last year.

Fifa 13

The most controversial element is likely to be the push/pull option, located on the B button, which allows players to start physically grabbing and shoving an opponent before they've even received the ball, potentially stealing possession.

It needs to remain within the laws of the game though and yellow cards will be shown for persistent muggers. More subtly, defenders will now be able to simply step in front of attackers to gain possession, rather than going in with a risky tackle – this will also allow you to shepherd the ball out when it's approaching the touchline.

In play, what this all adds up to is a noticeably more springy, improvisational game. The ball rebounds off shins and backs, or richochets between players, squirming out at unforseen angles.

While players were certainly capable of clattering into each other in Fifa 12, there is more sense of controllable aggression here, thanks to the push/pull mechanism – even though the ramifications of a nudge in the attacker's back might not always be favourable, given the frisky new physics.

As for the dribbling system, pushing both triggers while on the ball gets you a revised close control mode in which your player simultaneously strafes and dribbles, while facing the goal or the incoming defender. The system is much more expansive than previous iterations, allowing you to cover a lot more ground and really tease at the back line, looking for opportunities to sell the defender one way, before darting the other – apparently, they've taken elements of the skilful ball control engine from Fifa Street and added them to the main Fifa 13 system, via the left analogue stick.

"We wanted you to be able to really enjoy those moments when you're attacking goal," says Rutter. "Ronaldo will chop the ball one way then burst round the other side – this is something you can do in Fifa now. It's triggered contextually, so it'll happen automatically, but you can also instigate it yourself. This idea that you can lure the defender in then ghost past them at speed is one we've always wanted to achieve, and being able to do it while facing the goal is great."

Part of the refinement has involved actually reducing the ability of some players. First touch control has gone through the mincer: "We're now calculating the outcomes of the player receiving a ball, based on context," says Rutter, who also tells us the new system is based on the shooting engine, and will give defenders new opportunities to take the ball from the attacker – and vice-versa.

Fifa 13

"How the ball is spinning, the speed it's traveling, whether it's rising or falling … and also the position of the player, whether he's running, whether there's a defender pushing him – all detemine whether he'll be successful when the ball lands at his feet."

In effect, a 50-rated defender won't be gracefully receiving long distance passes on one perfectly outstretched foot anymore. "It's not realistic, it's not football," says Rutter. "We need to allow for variety, drama and unpredictability. You're going to have to think more intelligently about how you're going to control the ball in difficult situations."

Another interesting change is in the freekick system, which I've always had problems with in Fifa. You're now able to line up several players to pull off feints and fakes before actually taking the kick.

Meanwhile, if you're defending, you can add extra players to a wall and hit a button to make them jump and reform, or even sneak forward (but the player you're in control of will get carded if he tries it on too much). For many, this won't address the single biggest criticism of the Fifa freekick mechanic – the sheer difficulty of scoring from a set-piece – but it at least adds some more options.

There is clearly some balancing to do elsewhere. If there is to be pushing and pulling, you want it to be immediately effective; especially when you have a juggernaut like Micah Richards applying pressure to Jermain Defoe.

However, on several occasions I had to virtually attack the opposing player to get him off balance. Also, turning on the ball feels a little slow, so the spinning, squirted passes that Tevez often feeds to his co-strikers feel tantalisingly out of reach.

Nuanced is probably the right word for it all. Fans who were beginning to read – and even tire of – the staccato physical quirks of the last title, will find a whole new range of possibilities and outcomes. Fifa 13 may not currently look like an extraordinarily different beast to Fifa 12, but under the hood, it's seeking to tweak and fine tune what worked and quietly eliminate what didn't.

And of course, there will be changes to the game's range of modes, including its ever-growing online component – all of which we'll deal with in another article. For now, a roomful of games writers are getting their hands on the immediate future of the Fifa simulation – and they're enjoying every second.