All the possible scenarios as Europe's finest battle it out to make the quarter-finals, but who needs what to progress?
Munster v Racing 92
Munster have already qualified after defeating Glasgow at Scotstoun last weekend. If they can beat Racing 92 on Saturday, they’re guaranteed a home quarter-final.
They could still get a top four-seeding with a loss – though it seems unlikely given Wasps are only three points short of Munster and take on Zebre this weekend. Meanwhile, Racing 92 sit at the bottom of the pool with no hope of qualification.
Leicester Tigers v Glasgow Warriors
With only two wins to their name, Leicester are also out of the competition. Glasgow on the other hand will qualify with a win at Welford Road and may still scrape through if they lose, though this would be dependent on a defensive bonus point and many fixtures going their way.
Zebre v Wasps
It seems inevitable that Wasps come away from this meeting with five points. Other than that, who knows what will happen with this pool. As long as Connacht do not secure a bonus point victory and Wasps do, the men from Coventry should progress as they came away from their clashes with the Irish side with more match points.
Toulouse v Connacht
If Connacht win this one with a bonus point, they’ll finish top of pool two and could even get a home quarter-final if the right teams lose elsewhere. Toulouse, though, need wins both for themselves and Zebre to be in with any chance of qualifying at all.
In fact, as there is a four-point gap between Connacht and Toulouse, Toulouse would need to win with a bonus point and ensure Connacht do not gain any bonus points to escape the pool.
If Connacht score more than four tries or lose by less than seven points, the two sides will finish on 19 points but Connacht will go through based on points scored in their other match against les rouges et noirs.
Sale Sharks v Scarlets
After Chris Ashton’s equalising 82nd minute try in Wales last Sunday, Scarlets can no longer make it to the knock-out stages. Though a bonus-point win would see them finish equal with Toulon on 15 points, they would lose out to the French side in the head-to-head. With zero points in the competition so far, Sale are not playing for qualification either.
Saracens v Toulon
Toulon must take five points from this game and ensure Saracens leave with zero if they want to finish top of pool three. Any other outcome will leave Saracens as the leaders and a win would mean the English side gets to play their quarter final at Allianz Park. To qualify, Toulon need two points, either from a draw or a loss with two bonus points.
Castres v Leinster
Leinster have the most points in the competition so far, equal with Clermont, and if they go to Castres and take away a maximum five points then they could finish top of the seedings come the end of the weekend. Castres meanwhile are not completely dead and buried on ten points, but would need a bonus-point win and other results to go their way to possibly be a runner-up.
Montpellier v Northampton
Northampton, remarkably, also have a chance, but need a bonus-point win and other teams to lose to get one of those runners-up places. That's asking a lot however – Glasgow need to lose to Leicester by about 130 points – and Montpellier have their own hopes of making the last eight heading into Saturday in the knowledge that a win with a bonus point would put them in the chase for the one of the last runners-up places. They need Toulon and Exeter to pick up no points.
Ulster v Bordeaux-Bègles
Ulster's hopes are not quite over, but their demands are lengthy; Castres to lose to Leinster, Exeter to lose to Clermont, Glasgow to be thrashed by close to 60 points, and they need Northampton to win at Montpellier but fail to score four tries. Slim hopes then.
UBB on the other hand are a point better off and that opens up a window of sorts. First they need to win with a bonus point in Belfast and that Castres don't pick up a bonus-point win. Toulon must then pick up nothing from their trip to Saracens and have a worse points difference than UBB.
Clermont v Exeter Chiefs
That excellent win over Ulster last Sunday gave Exeter's hopes a bit of life, going into the weekend on 11 points. The Stade Marcel-Michelin is a fairly unforgiving venue but a win with a bonus point would put Exeter in a great position to go through as a runner-up. Prepare for more last-gasp drama much like last season if the following happens; If Toulon lose without any bonus points and Glasgow pick up only one point at Leicester, Exeter advance.
Clermont meanwhile are in the comfier position heading into Sunday, knowing that a win gives them a shot of finishing as the number one seed.