Team profiles and squad lists of the fours groups
Captain: Stuart Board. Coach: Andy Flower England defend the World Twenty20 title they won in the Caribbean two years ago without 2010 man of the tournament Kevin Pietersen, who remains in international exile after repeated run-ins with team officials.
Much will depend on how the likes of Alex Hales, effectively Pietersen's replacement, and the rest of the top order cope on the kind of spin-friendly pitches where England's batsmen have so often struggled in the past.
Left-arm spinner Danny Briggs, a star performer for English domestic Twenty20 champions Hampshire, could be important especially if experienced off-spinner Graeme Swann remains troubled by an elbow problem.
Pace bowling all-rounder Stuart Broad, one of eight survivors from the 2010 squad, captains the side, with Jade Dernbach's various slower deliveries set for their sternest test yet.
England squad: Stuart Broad (capt), Jonathan Bairstow, Ravi Bopara, Tim Bresnan, Danny Briggs, Jos Buttler, Jade Dernbach, Steven Finn, Alex Hales, Craig Kieswetter, Michael Lumb, Eoin Morgan, Samit Patel, Graeme Swann, Luke Wright.
India won the inaugural World Twenty20 in South Africa in 2007, but couldn't live up to their billing in the next two editions as they failed to qualify for the semi-finals in England and the West Indies.
Batting will be India's main strength as Virender Sehwag, Gautam Gambhir, Virat Kohli, Yuvraj and Dhoni are all capable of dominating any attack with their exciting strokeplay.
Yuvraj impressed with his power-hitting in the inaugural edition, smashing six sixes in an over from England paceman Stuart Broad at Durban in his 16-ball 58 to set up his team's victory. He also played a big role in India's 50-over World Cup triumph at home last year, scoring 362 runs and grabbing 15 wickets in nine matches to be named man of the tournament.
The spotlight will also be on off-spinner Harbhajan Singh, who is making a comeback after being ignored since August last year.
India squad: Mahendra Singh Dhoni (capt), Gautam Gambhir, Virender Sehwag, Suresh Raina, Virat Kohli, Yuvraj Singh, Irfan Pathan, Ravichandran Ashwin, Zaheer Khan, Lakshmipathy Balaji, Ashok Dinda, Rohit Sharma, Piyush Chawla, Harbhajan Singh, Manoj Tiwary.
Twenty20 cricket suits the maverick style of Afghan cricketers. Their batsmen are not afraid to play shots in the air and take great delight in smashing the best bowlers out of the ground. The batsmen to watch out for are opener Karim Sadiq, wicketkeeper Mohammad Shahzad, Mohammad Nabi and Asghar Stanikzai, who are all attractive strokemakers.
Skipper Nawroz Mangal leads the spin attack alongside Sadiq and Samiullah Shenwari, while the big-built Shapoor Zadran and Dawlat Zadran are new-ball bowlers capable of striking vital blows. Both England and India can ill-afford to take the Afghans lightly in the preliminary group stage.
Afghanistan squad: Nawroz Mangal (capt), Dawlat Zadran, Gulbodin Naib, Hamid Hassan, Izatullah Dawlatzai, Karim Sadiq, Javed Ahmadi, Mohammad Nasim Baras, Mohammad Nabi, Mohammad Shahzad, Asghar Stanikzai, Najibullah Zadran, Samiullah Shenwari, Shafiqullah Shafaq, Shapoor Zadran. Top Group B
George Bailey leads the Twenty20 squad to Sri Lanka looking to win the only major title that has eluded Australia. Desperate situations call for desperate measures and 41-year-old left-armer Brad Hogg has been brought in to bolster the spin attack.
If Hogg will be the oldest player in the competition, 19-year-old fast bowler Pat Cummins will be one of the youngest. Cummins, Clint McKay, Ben Hilfenhaus and Mitchell Starc will form the pace attack with support from all-rounders Daniel Christian and Shane Watson.
The hard-hitting Cameron White has also been brought back in a middle-order that includes the Hussey brothers, David and Michael, while David Warner is expected to provide an aggressive start.
Australia squad: George Bailey (capt), David Warner, Shane Watson, Matthew Wade, David Hussey, Michael Hussey, Cameron White, Daniel Christian, Glenn Maxwell, Brad Hogg, Xavier Doherty, Clint McKay, Mitchell Starc, Pat Cummins, Ben Hilfenhaus.
The IPL has thrown up several match-winners from the Caribbean in the shortest format of the game. Any side that possesses explosive batsmen such as Chris Gayle and Kieron Pollard, backed by solid all-rounders in Dwayne Bravo, Marlon Samuels and Andre Russell, and a superb spinner in Sunil Narine, can never be counted out.
Attacking cricket, the hallmark of the West Indies game, is ideally suited to the Twenty20 version. And with conditions in Sri Lanka -- slow, batsmen-oriented wickets -- similar to those in the IPL, the West Indies will not find it tough to adjust. Darren Sammy's men are capable of springing a few surprises.
West Indies squad: Darren Sammy (capt), Dwayne Bravo, Samuel Badree, Darren Bravo, Johnson Charles, Fidel Edwards, Chris Gayle, Kieron Pollard, Sunil Narine, Denesh Ramdin, Ravi Rampaul, Andre Russell, Marlon Samuels, Lendl Simmons, Dwayne Smith.
Their squad has plenty of subcontinental experience, with Kevin O'Brien having compiled the fastest-ever hundred in the 50-over World Cup during Ireland's stunning win over England in Bangalore last year.
William Porterfield, the captain and one of several county cricketers in the squad, will aim to lead from the front with the bat, as newcomer Tim Murtagh looks to bolster a seam attack featuring Australia-born veteran Trent Johnston.
Much will be expected of talented Somerset left-arm spinner George Dockrell, 20, on Sri Lankan pitches renowned for taking turn.
Ireland squad: William Porterfield (capt), Alex Cusack, George Dockrell, Trent Johnston, Nigel Jones, Ed Joyce, Tim Murtagh, Kevin O'Brien, Niall O'Brien, Boyd Rankin, Paul Stirling, Max Sorensen, Stuart Thompson, Andrew White, Gary Wilson.
Top Group C
South Africa remain strong contenders in any form of the game, including Twenty20. Opening batsman Richard Levi is able to hit ferociously in the power-play overs and is backed by more orthodox world-class batsmen in AB de Villiers, Jacques Kallis and Hashim Amla. Then there is Albie Morkel, the hard-hitting 'finisher'.
Dale Steyn and Morne Morkel provide top-quality fast bowling, Lonwabo Tsotsobe is a naggingly accurate left-armer and there are capable spin bowlers in Johan Botha, Robin Peterson, Faf Du Plessis and JP Duminy.
South Africa have not won a 50-over World Cup or the World Twenty20 despite consistently being among the favourites. They now get a chance to set the record straight as they go into the World Twenty20 as international cricket's most feared side.
South Africa squad: AB de Villiers (capt), Hashim Amla, Farhaan Behardien, Johan Botha, JP Duminy, Faf du Plessis, Jacques Kallis, Richard Levi, Albie Morkel, Morne Morkel, Justin Ontong, Wayne Parnell, Robin Peterson, Dale Steyn, Lonwabo Tsotsobe.
Inspired by crowd support and aided by familiar conditions, Mahela Jayawardene's team start as unofficial favourites with batsmen and bowlers to rise to the big occasion.
The home team will not be short of T20 experience, having played two matches against Pakistan and one against India in recent months. Most of their players also recently figured in the inaugural Sri Lankan Premier League.
They have excellent batsmen in Tillakaratne Dilshan, Jayawardene and Kumar Sangakkara, and talented all-rounders in Angelo Mathews and Thisara Perera. Sri Lanka also have a match-winning paceman in Lasith Malinga, and the return of unorthodox spinner Ajantha Mendis adds variety to their attack.
Sri Lanka: Mahela Jayawardene (capt), Angelo Mathews, Kumar Sangakkara, Tillakaratne Dilshan, Lahiru Thirimanne, Jeevan Mendis, Dilshan Munaweera, Thisara Perera, Lasith Malinga, Nuwan Kulasekara, Rangana Herath, Ajantha Mendis, Dinesh Chandimal, Shaminda Eranga, Akila Dananjaya. ZIMBABWE
Zimbabwe have only a small number of potential match-winners, but if they perform at their peak they are a side that cannot be discounted. Their bowling is steady, with the spin of Graeme Cremer, Prosper Utseya and veteran Ray Price likely to be a key factor on the slow pitches of Sri Lanka, and they are an athletic fielding team.
Although Zimbabwe have lost their last 12 official T20 internationals, they had two morale-boosting wins in three matches against a strong South African XI in a triangular tournament in Harare in June. Zimbabwe cruised to a nine-wicket win against their neighbours in the final, with their top three batsmen, Hamilton Masakadza, Vusi Sibanda and Taylor all making runs. They will rely heavily on these three in Sri Lanka, with Elton Chigumbura also capable of hitting hard in the closing overs.
Zimbabwe squad: Brendan Taylor (capt), Vusi Sibanda, Hamilton Masakadza, Stuart Matsikenyeri, Malcolm Waller, Elton Chigumbura, Craig Ervine, Graeme Cremer, Ray Price, Kyle Jarvis, Chris Mpofu, Richard Muzhange, Brian Vitori, Prosper Utseya, Forster Mutizwa.
Top Group D
Pakistan's World Twenty20 record also shows they are a side not to be taken lightly. They were runners-up to India in the inaugural edition in 2007, won the next one in England in 2009 and lost in the semi-finals of the last tournament in the Caribbean a year later.
Pakistan have a strong batting line-up with the recalled Kamran Akmal and Mohammad Hafeez at the top of the order, with Umar Akmal, Shahid Afridi and Abdul Razzaq providing a power-packed middle-order. They also have one of the most potent bowling attacks, with seamer Umar Gul backed by prolific spinner Saeed Ajmal, Afridi and Hafeez.
Pakistan squad: Mohammad Hafeez (capt), Imran Nazir, Nasir Jamshed, Asad Shafiq, Shoaib Malik, Umar Akmal, Kamran Akmal, Abdul Razzaq, Shahid Afridi, Sohail Tanveer, Umar Gul, Saeed Ajmal, Raza Hasan, Yasir Arafat, Mohammad Sami.
Ross Taylor's side will be glad to have the influential Daniel Vettori back in the side after recovering from a nagging groin injury. The former captain not only adds the necessary experience at the top level but remains one of the most potent let-arm spinners in the game and a reliable batsman down the order.
Brendon McCullum is the go-to man for the Kiwis, capable of destroying any bowling attack on his day. Taylor, Martin Guptill, Jacob Oram and James Franklin are others who New Zealand will bank on to deliver. The Black Caps are known to rise to the big occasion, after shocking favourites South Africa in the quarter-finals of last year's 50-over World Cup. Their fans will be looking for an encore in Sri Lanka.
New Zealand squad: Ross Taylor (capt), Martin Guptill, Rob Nicol, Brendon McCullum, Kane Williamson, BJ Watling, James Franklin, Jacob Oram, Nathan McCullum, Daniel Vettori, Kyle Mills, Doug Bracewell, Tim Southee, Ronnie Hira, Adam Milne.
They began the inaugural 2007 World Twenty20 in South Africa on a sensational note when they knocked the West Indies out of the tournament with a six-wicket victory, qualifying for the second round.
Bangladesh failed to make it to the second round in the next two editions in England (2009) and the West Indies (2010), but have produced some encouraging results in recent months.
They beat 50-over World Cup champions India, and runners-up Sri Lanka, in the Asia Cup at home in March before losing to Pakistan in the final.
Bangladesh also won four of their six T20 matches on their tour of Europe in July, including a 3-0 sweep against Ireland.
Led by wicketkeeper-batsman Mushfiqur Rahim, Bangladesh have a hard-hitting opener in Tamim Iqbal and talented all-rounder in Shakib Al Hasan who are capable of winning matches.
Bangladesh squad: Mushfiqur Rahim (capt), Mohammad Mahmudullah, Tamim Iqbal, Mohammad Ashraful, Junaid Siddique, Jahurul Islam, Shakib Al Hasan, Nasir Hossain, Ziaur Rahman, Elias Sunny, Abdur Razzak, Mashrafe Mortaza, Shafiul Islam, Farhad Reza, Abul Hasan.