If 'C' is for 'Christmas and 'S' is for 'Santa' at this time of year, then 'D' is for 'Derby' - and there are plenty of them in the Magners League over the Festive period.
Big crowds, explosive action and the best possible reason to leave the house will be served up in four countries over a 10 day period that will see the best of friends become the worst of enemies.
Just looking at the list of traditional battles makes the adrenalin start to rush:
- Edinburgh v Glasgow twice in the 1871 challenge
- reigning champions the Ospreys v Scarlets
- Dragons v Blues and then Blues v Ospreys
- Connacht v Munster and then Leinster v Connacht
- Ulster v Leinster and then Munster v Ulster
Many of those matches date back to the 19th century, but this Christmas will see the start of a new rivalry that promises to be every bit as intense as the traditional fixtures - Benetton Treviso v Aironi Rugby.
"Aironi are based in Viadana and the fact that we beat Viadana in the last two Italian Championship finals is going to be grating on them. The two games over Christmas are going to be vital for both clubs," confessed Benetton Treviso head coach Franco Smith.
"It was always going to take Aironi a bit of time to settle as a completely new team, but their win over Biarritz Olympique proved they are getting better and are capable of beating anyone on their day.
"There are a lot of players in both sides who know each other very well and there will be points to be proved. The fact that every other team in the Mangers League has taken points off Aironi means the pressure will be on us to do the same."
The first meeting between the two teams in Treviso will kick-off the Festive fixtures on Christmas Eve and the bulk of the Italian national team will be on display. The return game in Viadana will be on New Year's Eve.
The only other back-to-back derby clash will be the 1872 clashes between Glasgow Warriors and Edinburgh. This rivalry is the oldest in world rugby and dates back 138 years.
The first game will be at the Firhill Stadium on Monday, 27 December (kick-off 5.35 pm) with the return coming at Murrayfield six days later.
In Ireland, current Magners League leaders Munster will be hoping not to fail again when they travel to Galway on St Stephen's Day. There were 5,000 packed into the Sportsground two years ago to see Connacht win 12-6 to notch their first victory over their old rivals in 22 years and claim their first victory over them on home soil since 1979.
Connacht then face a challenging trip to Dublin to face Leinster, who launch their round of Inter-Pro derbies with a trip to Ravenhill on Monday, 27 December. A win there would allow Leinster to leapfrog their rivals in the table.
Ulster, fresh from their back-to-back victories over Bath in the Heineken Cup, will be full of confidence and hoping to not only move into the Play-Off places, but also eat into Munster's lead at the top when they make the trip to Thomond Park on New Year's Day.
The Ospreys are almost ready to put the 'sold-out' signs up for their Boxing Day clash with the high flying Scarlets at the Liberty Stadium. Currently the top placed Welsh region in the Magners League, Nigel Davies'side are also leading their Heineken Cup Pool after four rounds.
It has been an amazing turn-around in fortunes for the Scarlets, who last season finished one off the bottom of the Magners League with a mere 29 points from 18 games, and they go into the Christmas period four points behind Munster with 32 points.
The Dragons will have Tom Willis, Luke Charteris and Jason Tovey back in harness for their clash with the Blues on Monday, 27 December in a fixture that has its origins 134 years ago.
That's when Newport first met Cardiff on the Newport Marshes in a game that launched one of the greatest rivalries in rugby. These days, the two clubs still meet in the Principality Premiership, but the Dragons and Blues have taken the rivalry between the two Welsh cities to a new level in the Magners League.
The Blues are currently lying in third place in the table and have the Ospreys due to visit them on New Year's Eve, while the Dragons head to Parc y Scarlets the next day.
If you can't get a ticket to one of the big games, then the good news is that every one of the 12 Festive fixtures will be available live on TV.
Have a great Christmas and look out for a fantastic run-in to the second Magners League Grand Final in the New Year.