What is it?
When is it?
Sunday 22 September - ie tomorrow. It will be played at the Yokohama International Stadium in Yokohama City on the east coast of Japan.
What time is kick-off?
Kick-off for this one is at 8:45am BST, 4.45pm local time.
What TV channel is it on?
The game will be broadcast live on ITV, with streaming and replays available on the ITV Hub. Alternatively, you can follow all the action here with Telegraph Sport.
What is the latest team news?
Ireland must do without the experience of Rob Kearney and Keith Earls in their back three for the World Cup opener against Scotland after the pair ran out of time to prove their fitness on Friday.
Munster's Andrew Conway will take the place of Ireland's record World Cup try scorer Earls on the wing while Leinster's 22-year-old flyer Jordan Larmour comes in for Kearney, who was set to start in his third World Cup.
With 170 caps between the two injured men and influential centre Robbie Henshaw already ruled out, the Johnny Sexton-marshalled Irish backline will feature five World Cup debutants in Sunday's Pool A clash.
In the pack, coach Joe Schmidt opted for a back row of Peter O'Mahony, CJ Stander and Josh van der Flier while Iain Henderson partners James Ryan at lock.
Ireland: 15-Jordan Larmour, 14-Andrew Conway, 13-Garry Ringrose, 12-Bundee Aki, 11-Jacob Stockdale, 10-Johnny Sexton, 9-Conor Murray, 8-CJ Stander, 7-Josh van der Flier, 6-Peter O'Mahony, 5-James Ryan, 4-Iain Henderson, 3-Tadhg Furlong, 2-Rory Best (captain), 1-Cian Healy
Gregor Townsend has opted to name an experienced line-up ahead of Scotland's World Cup opener against Ireland.
Skipper Stuart McInally will lead out a team boasting 630 caps for the Pool A clash at Yokohama's International Stadium.
Exeter full-back Stuart Hogg and Saracens wing Sean Maitland return to the back three after missing this month's final warm-up Test against Georgia to partner Glasgow's Tommy Seymour.
Former skipper Greig Laidlaw joins playmaker Finn Russell at half-back, with centres Sam Johnson and Duncan Taylor the only backs to be reinstated from the 36-9 win over the Lelos.
Scotland: 15-Stuart Hogg, 14-Tommy Seymour, 13-Duncan Taylor, 12-Sam Johnson, 11-Sean Maitland, 10-Finn Russell, 9-Greig Laidlaw, 8-Ryan Wilson, 7-Hamish Watson, 6-John Barclay, 5-Jonny Gray, 4-Grant Gilchrist, 3-Willem Nel, 2-Stuart McInally (captain), 1-Allan Dell
What is their head-to-head record?
In 133 games the record between the two teams has been very even, Ireland have won 62 matches whilst Scotland have won 66 with five matches drawn and one abandoned due to a waterlogged pitch. The largest winning margin between the two was a 40-10 win to Ireland in the 2015 Six Nations.
What are they saying?
Ireland's Joe Schmidt:
"It was a difficult thing right from the start to have the 45 that we had. We went down to 40 players and to go from 40 down to 31 was really difficult, but we had a process whereby we looked back through every training, looked through the games.
“There were some guys who obviously had more experience and probably had more credit in the bank and were more established, and there were other guys who were trying to force their way into group. Trying to get a balance of current form versus previous performance, it’s always a very very difficult conundrum to try to solve.
“It was one of those typical selection meetings where maybe 20-25 of the players are listed straight away, and it’s those ones where you’re are trying to get balance where it’s very difficult to choose between two players – and two players offer slightly different things.
“You’re trying then to narrow down and trying to get the best balance across the squad of the entire 31 because that’s part of what you need to do because you’ve got to make sure you have cover that’s immediate. Even though you can replace players, there is obviously a big time delay in that.”
Scotland's Gregor Townsend:
"Success would be playing to our best. We’ve got to play to our potential on 22 September (in their opening game against Ireland) and keep that going right through the tournament.
“We know, and we’ve seen it, that when we play to our best we’re a match for any team in the world. Whether that’s how we defended and attacked against New Zealand, or against England or Australia, against those top teams in the world when we’ve played our best we’ve won those games. Obviously against New Zealand, we almost beat them. “We’ve got a stronger squad now than we’ve ever had. To have everybody available now should mean that we’ve never been in a better position over the last two or three years to play at our best.”
What are the betting odds?
Ireland to win:3/10
Scotland to win: 13/5
Read our guide on betting tips and latest odds.
What is our prediction?
With Ireland topping the world rankings they have to be the favourites for this game, with this being Joe Schmidt's last tournament in charge as well the players will be determined for him to go out with a bang. Scotland sit seventh in the world rankings but could cause an upset as the even record between the two sides shows. A win for Ireland is, however, the most likely outcome.
Predicted Score: Ireland 29 Scotland 17
Read our expert's predictions for the tournament.