Richard Kruse, Britain's best bet for a first Olympic fencing medal since 1964, could have to beat two of the world's top six next Tuesday just to give himself a chance.
The 28-year-old Londoner - he turns 29 the day before the competition - learnt on Thursday he will begin his bid against Russian Artur Akhmatkhuzin, ranked six places below him at 21st, in the last 32.
To reach the quarter-finals, as he did in Athens eight years ago, Kruse might then have to topple China's fourth-ranked Ma Jianfei and after that sixth-ranked Korean Choi Byungchu, a former world championship bronze medallist, could block his path.
However, Kruse, who won bronze in the recent European Championships, told Press Association Sport: "I've got a top eight already. What else can I celebrate other than a podium? That's my dream."
James Davis is also given a first-round bye before having to tackle Germany's four-time world champion Peter Joppich, while Husayn Rosowsky will have to meet Italy's current world number one Andrea Cassara if he first overcomes Tunisian Mohamed Samandi.
The fencing programme starts on Saturday with an all-British clash in the women's foil. Polish-born Natalia Sheppard, who came through a qualifying competition to earn her spot, will take on team-mate Sophie Troiano in the first round. Sheppard is ranked 42nd, Troiano 100th and whoever wins will then face France's world number six Corinne Maitrejean.
Scot Anna Bentley is the other member of the foil team. She is ranked 165th and has an opening fight against Canadian Monica Peterson, 122 places above her. America's world number five Lee Kiefer waits for the winner.
James Honeybone is the only Briton in the men's sabre on Sunday. If he beats Valery Pryiemka, from Belarus, it will be Italy's world number four Aldo Montano next.
Another fourth-ranked fencer, Romanian Simona Gherman, will be Corinna Lawrence's second round opponent in the women's epee on Monday if she can first overcome Chilean Caterin Bravo Aranguiz, at 66th in the world 23 spots below her.
In Wednesday's women's sabre Louise Bond-Williams goes straight in against world number four Vassiliki Vougiaka, of Greece, while Sophie Williams meets Italy's world number six Irene Vecchi. Britain also has teams in the men's and women's foil, but both will have to face top seeds Italy if they win first round matches against Egypt.