|Welsh derby Pro12 Judgement Day IV: Blues v Ospreys & Dragons v Scarlets|
|Date: Saturday, 30 April Venue: Principality Stadium|
|Blues v Ospreys, kick-off 14:30 BST: Live on BBC Two Wales & online, full commentary on BBC Radio Wales, BBC Radio Cymru, BBC Sport website and BBC Sport app. Highlights online & on Scrum V BBC Two Wales Sunday 18:00.|
|Dragons v Scarlets, kick-off 17:00 BST: Live on S4C, full commentary on BBC Radio Wales, BBC Radio Cymru, BBC Sport website and BBC Sport app. Highlights online & on Scrum V BBC Two Wales Sunday 18:00.|
They call it Judgement Day, and on Saturday more than 60,000 fans will watch Wales' four rugby regions in action at the Principality Stadium in Cardiff.
But it is more than an end of season exhibition. Much more.
With two rounds of Pro12 matches remaining, play-off places and top-tier European qualification are on the line as well as local bragging rights.
So here's a quick guide to the matches, and what's on the line for the teams.
Blues v Ospreys (kick-off 14:30 BST)
With neither side serious contenders for the end-of-season play-offs, resurgent Blues and faltering Ospreys are fighting for European Champions Cup qualification.
Danny Wilson's eighth-placed Blues are one spot and three points ahead of their opponents but six points away from sixth place, which is effectively the final qualification position as the highest Italian finisher claims the seventh slot.
|Pro12: Remaining fixtures|
|Saturday, 30 April: Blues v Ospreys; Ulster v Leinster, Dragons v Scarlets|
|Saturday, 7 May, all kick-offs 15:00 BST: Connacht v Glasgow; Edinburgh v Blues; Leinster v Treviso; Munster v Scarlets; Ospreys v Ulster; Zebre v Dragons|
Even if they avenge last November's 13-6 defeat by Ospreys, the Cardiff region will be relying on Scarlets beating Munster at Thomond Park after the Irish team's bonus-point win over Edinburgh.
A win for Blues could set up a big final-day showdown at Edinburgh.
Friday night's win for Munster leaves Ospreys likely miss out on European rugby's top competition for the first time since the region's inception in 2004.
They will again be without Wales forwards Justin Tipuric (concussion) and Paul James (eye) and club captain Alun Wyn Jones (heel).
Form Guide: Cardiff Blues are looking for a fifth consecutive win; Ospreys have won two and lost two in their past four matches.
NG Dragons v Scarlets (kick-off 17:00 BST)
Scarlets could be Wales' first representatives in next season's European Champions Cup before this game kicks off - if Ospreys beat Blues without a bonus point.
That would secure their place as Wales' top side in the Pro12.
Ironically it was Scarlets' win in Swansea on 26 March that dealt a mortal blow to Ospreys' European ambitions.
After that result, the west Wales region looked a solid bet for a top-four finish to reach the end-of-season play-offs.
But home defeats against Blues and Glasgow - the latter a 46-10 hammering - have derailed coach Wayne Pivac's team, who now lie fifth.
A glance at the table would suggest Scarlets would be strong favourites against 10th-placed Dragons, but the men of Gwent have pushed everyone close this season - as their 10 losing bonus points attest.
And their 23-21 win over Gloucester in the European Challenge Cup quarter-final showed that on their day, Dragons can produce a shock.
Scarlets should finish as Wales' top side and qualify for the 2016-17 Champions Cup, while that train has long since departed from the Dragons' station. They will play in the second-tier Challenge Cup.
But a shock result here would leave Pivac's team vulnerable if Blues beat Ospreys - especially with a tough trip to Munster on the final day.
But a win here and a victory for Leinster at Ulster would see the Scarlets climb into the last play-off place.
Form guide: Scarlets have lost their past two league matches, but Dragons have lost their last eight Pro12 games.
What's at stake for Welsh rugby
Not so long ago Wales was guaranteed three places at Europe's top table.
In contrast to the national side's consistent challenge at European level, the regions have barely made a dent.
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The last Welsh side to reach the knockout stages of the top-flight tournament were Cardiff Blues in 2012.
If things go badly in the final two weeks of the Pro12 season Wales will end up with just one team in the Champions' Cup next season - the same as Italy.
And that would be a major setback following the restructuring of the tournament in 2013 and the new agreement for funding of the domestic game agreed in the same year.
|Pro12 European Champions Cup qualification|
|The highest placed team from Ireland, Scotland, Italy and Wales, then:|
|The three highest-placed teams in the final table who have not already qualified.|
On a positive note, two wins each for Blues and Scarlets would secure a second place for Wales in the Champions Cup.
However, Ospreys and Dragons fans might feel parochial interests trump national concerns.