As a traditional climber, Moffatt established some of the most intimidating routes at the time in Britain, which are still rarely repeated, and in particular, the Master's Wall (E7 6b) in 1983.

[7][8] In 1982, aged 19, Moffatt travelled to the United States, where he repeated America's hardest routes, and did the world's first-ever flash of a 7b+ (5.12c) with Super Crack in Shawangunks, and Equinox in Joshua Tree.

[1] In 1983, on returning home, Moffatt established his most dangerous traditional climbing route, Master's Wall[d] (E7 6b)[a] at Clogwyn Du'r Arddu.

[1] Later that summer, Moffatt focused on sport climbing, establishing Masterclass at Pen Trwyn, the first British 8a (5.13b) route.

[b][1] In June 1985, Moffatt did the first free ascent of the Yosemite's Lost Arrow Spire with Ron Kauk, as a live television event with an audience of over 30 million for ABC's Wide World of Sports.

[12] During 1985 to late 1986, Moffatt was largely out with a compressed nerve injury (initially mis-diagnosed as tendonitis), that required surgery and rehabilitation.

[1] On returning in 1987, Moffatt spent the next two years repeating the three hardest 8b+ (5.14a) routes in France (Le Rage de Vivre, Le Minumum, La Spectre des Surmutant in Buoux), and in the United States (Scarface, White Wedding, To Bolt Or Not To Be in Smith Rocks), while also creating his own 8b+ route, Stone Love in the Frankenjura in Germany.

[1] In May 1990, he returned to Pen Trwyn in Wales to create Liquid Ambar, Britain's first 8c (5.14b) route, and which has been regraded to 8c+ (5.14c), which would make it the world's first 8c+.

[c][8][14] Moffatt continued to travel widely, repeating Punks In The Gym 8b+ (5.14a) in 1992 in Australia, establishing Canada's first 8b (5.13d), The Big Kahuua, in 1993 in Ontario, and freeing routes such as Evolution 8c+ (5.14c) in 1995 at Ravens Tor.

[5][7] In September 1990, aged 27, Moffatt retired from competition climbing and at that time was rated first on the Association of Sport Climbers International (ASCI) rankings.

In 2006, the BBC said: "Jerry is one of, if not the greatest climbers of all time, and his name is known and highly respected in the global world of rock climbing".

[27] In a British context, Moffatt (and contemporaries such as Moon and Dawes) carried on the legacy of Peter Livesey and Ron Fawcett.

[6] Moffatt, and Moon, were also part of a new group of climbers, that included Germans Wolfgang Gullich, Kurt Albert, and Stefan Glowacz,[1][27] who were using new training techniques (e.g. campus board, plyometrics), and embracing bouldering, to materially improve their technique and the standard of routes they could climb.

[3] In April 1987, his younger brother Toby died aged 21 in the United States (in his autobiography, Moffatt says that he named his climb Liquid Ambar after the tree Liquidambar – although Moffatt spells it as two words[2] – in memory of Toby, who was a keen gardener and wished to plant such a tree on his return to England).