Heineken Cup permutations: what they need
The unbeaten champions need merely to beat Montpellier to confirm their placing as a top-four seeding and thus earn a guaranteed home draw in the quarter-finals for the third successive season.
A victory against Northampton will simplify matters, ensuring the unbeaten former champions are guaranteed a home quarter-final after missing out entirely last season.
Should they lose but collect a bonus point, they will be relying on favours elsewhere.
Should any four of Leinster, Toulouse, Saracens, Ulster and Edinburgh win -- Cardiff may also be a factor should they overcome a formidable try-scoring deficit -- Munster will slip out of the top four seedings.
If they lose without a bonus point -- ie by more than seven points -- they may have to rely on further favours from Connacht and Ulster, as Harlequins and Clermont may also have the opportunity to pass them.
Ulster require a win or a draw to top the pool against Clermont -- who have a crunch Top 14 tie five days later -- and secure qualification to the quarter-finals, but Connacht can still do them a favour if that doesn't happen.
Even if they fail to get the desired result in France, they could still go through as one of two best-placed runners-up as they have amassed 19 points so far. Those two runner-up spots can only come from Pools 2, 4 and 6.
In Pool 2, Cardiff and Edinburgh are both on 17 points -- two behind Ulster -- meaning that defeat for either side would see Ulster through. Cardiff host Racing Metro and Edinburgh are also at home against London Irish.
There is a similar situation in Pool 6, with Toulouse on 18 points and Harlequins on 16. Again, defeat for either side would almost certainly see Ulster progress. In simple terms, Ulster fans should be cheering on Racing Metro, London Irish, Gloucester (v Toulouse) and Connacht (v Harlequins).