Today's draw, held at the Tate Modern art gallery in London, left Scotland with their work cut out in Pool B, in the wake of coach Andy Robinson resigning last month following autumn losses to the All Blacks, South Africa and Tonga.
South Africa, the 1995 and 2007 world champions, will be favourites to take the pool, but Samoa could easily pip the Scots for second spot and and a quarter-final place from a group that could also feature Japan and either America or Canada.
Host nation England have been drawn in the same pool as Wales and Australia.England's group - Pool A - will be completed by two qualifiers, Oceania 1 (probably Fiji) and the play-off winner, possibly Uruguay.
Ireland have landed France, Italy, Americas 1 and Europe 2 in Pool D, while the All Blacks look to have secured the easiest pool, being bracketed alongside Argentina, Tonga, Europe 1 and Africa 1.
The tournament kicks off on September 18, 2015, with Twickenham staging the final six weeks later.
England, crowned 2003 world champions after they beat Australia in a gripping final, have never previously been drawn in the same World Cup group as Wales.
Their last World Cup meeting was during the 2003 tournament in Brisbane, when England trailed at half-time before securing a tense quarter-final triumph. And the last time England and Australia found themselves in the same pool was at the inaugural World Cup 25 years ago.
Wales, World Cup semi-finalists last year, have paid a price for dropping to ninth in the International Rugby Board rankings following successive autumn defeats against Argentina, Samoa, New Zealand and Australia.
It meant they were in the third band of countries for today's draw, increasing the prospect of a punishing group, and so it has proved.
Despite their recent struggles, though, Wales will be confident they can progress to the quarter-finals, having won two Six Nations titles and Grand Slams during head coach Warren Gatland's reign.
Ireland, meanwhile, will should feel reasonably pleased with the Pool D make-up, with their game against France likely to decide who finishes top.
Italy will fancy their chances of upsetting the status quo, but they do not have a great World Cup record. The group is likely to be completed by America or Canada and one of Georgia, Russia and Romania.
New Zealand, the runaway Pool C favourites, will be wary of Rugby Championship rivals Argentina, yet Tonga, Europe 1 (probably Georgia and Russia) and Africa 1 (probably Namibia) provide no threat.
The eight pool places to be filled by qualifiers will be finalised by the end of 2014.
If the 2015 tournament follows its current seeding path, then the quarter-finals would see South Africa face England, New Zealand tackle Ireland, Australia meet Samoa and France take on Argentina.