He and his comic partner Peter Cook first came to fame as key members of Beyond the Fringe. Their double act was subsequently parlayed into further stage revues, the long-running comedy sketch show Not Only...But Also..., and later the rather extreme comedy duo in Britain known as Derek & Clive (this was used as a means of perfoming all the material deemed too extreme, or in too bad taste, for television). After their partnership dissolved in the late 1970s, Moore moved on to international success via Hollywood with the films 10 and especially Arthur, the latter of which yielded him an Academy Award nomination for Best Actor.
On top of all this, having been trained as a classical musician at Oxbridge Moore was also an acclaimed classical and jazz pianist whose improvisations were praised by some of the best.
- The Wrong Box (1966)
- Bedazzled (1967)
- Foul Play (1978)
- 10 (1979)
- Wholly Moses! (1980)
- Arthur (1981)
- Lovesick (1983)
- Romantic Comedy (1983)
- Unfaithfully Yours (1984)
- Best Defense (1984)
- Micki And Maude (1984)
- Santa Claus: The Movie (1985)
- Like Father, Like Son (1987)
- Arthur 2: On the Rocks (1988)
- Crazy People (1990)
- Blame It on the Bellboy (1992)
Tropes set to improvised jazz rhythms by Dud include:
- Breakup Breakout: Moore's ruptured partnership with Peter Cook was the spur that led him to try his luck in America. After several critically acclaimed movies he became a superstar. Peter Cook remained in relative obscurity, his comic genius overshadowed by his alcoholism, taking only bit parts in TV and movies but active in the satirical magazine he co-founded, Private Eye.
- Butt-Monkey: Moore's perception that he was this to Peter Cook, not only in their TV and stage work but in their friendship as well, ultimately ruptured the partnership and severely strained their friendship. Cook, when drunk, could be notoriously cutting and scathing when referring to Moore, even to his face and in public.
- Cluster F-Bomb: "Derek and Clive" created the Cluster-F-Atomic-Weapon, and tended to refer to Country Matters as if the word were punctuation.
- Corpsing: Cook was notorious for provoking this in Moore.
- Dream-Crushing Handicap: The famous sketch in which Dudley plays a one-legged man auditioning for the part of Tarzan.
- Drinking on Duty: Moore's other grievance with Cook was a perception that his alcohol dependency was seriously out of hand and that Moore was left to carry the performances. Tragically, Moore's death was due to a degenerative neural disease called progressive supranuclear palsy, which even after its belated diagnosis led people to believe he had taken to the bottle and was becoming alcoholic himself (that his most famous movie character was an alcoholic didn't help any).
- Getting Crap Past the Radar: There's some evidence of this in his and Cook's early TV work. But not even bothering with the radar - the "Derek and Clive" performances, originally not meant for release and done for private circulation, but which "escaped" and later became a series of best-selling comedy albums.
- Kavorka Man: Despite his diminutive size and physical disability note , Moore starred opposite some beautiful women in his films and had a disproportionate amount of romantic success in private life. The nickname "sex thimble" was applied to him by envious friends.
- The Not Catch: The ''Jump, you fucker, jump!" song from Derek and Clive, written and performed by Dudley, in which a man standing on a high ledge is encouraged to leap... only for the people underneath to fail to catch him, as watching him splat is more of a laugh.
- Refuge in Audacity: Ostensibly the entire point (and appeal for audiences) of the Derek and Clive recordings in all their drunken madness as Pete and Dud tackle all manner of things in the most vulgar way possible.
- Straight Man: Most of the time Moore was this to Cook, but the roles were easily reversed.
- "The Reason You Suck" Speech: An odd variant; the pair indulge in this in the opening to Derek and Clive's 'Come Again' record, mocking the listener for buying their record, that the listener's children will starve due to the wasted money, forcing the listener to endure periods of silence before promptly declaring that the listenr can't even return the item as they've likely gotten so angry they've thrown the record out the window.
- Up to Eleven: The "Derek and Clive" sketches, which were outrageously extreme and even for their day, racially offensive, derogatory to women, and often extremely homophobic. Pete and Dud appeared to take pride in this and seemed to be competing as to who could break the largest number of taboos in a single sentence. The 2004 semi-autobiographical film Not Only But Always... suggests that the sheer audacity of the early Derek and Clive recordings prompted the duo to make more while Dudley was trying to break Hollywood.