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The ACE Publishing Paperback Catalogue
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Covering 30+ Years of Paperback Publications ~ 1950s thru 1980s
Compiled from many sources both in print and online.
Online since 2017 as an extra-section covering the ACE Doubles Books at Andre-Norton-Books.com and moved here in March of 2025
Last Updated 09-13-25

ACE Single Title Paperbacks

40000 thru 49999

 

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TITLE FRONT COVER BACK COVER EXTRA IMAGE/S AUTHOR GENRE DATE PRICE EDITION COVER BY NOTES
40590 Too Sweet To Die: A John Easy Mystey #2 Ron Goulart Mystery 1972 1st ACE printing and PBO Elaine Duillo Second of 'John Easy' mysteries, a Hollywood private eye by RON GOULART
40591 One Grave Too Many: A John Easy Mystey #4 Ron Goulart Mystery 1974 1st ACE printing and PBO Tom Adams December 1974 ~~ Fourth of 'John Easy' mysteries, a Hollywood private eye by RON GOULART. Note that the third volume of this series is ACE 75945 (1973).
40850 -8 The Journey of Joenes Robert Sheckley Sci-Fi 1979 1st ACE printing David Bergen Original title: Journey Beyond Tomorrow
Previously issued way back in 1962 under the title of “Journey Beyond Tomorrow” by Signet Books. This is the first edition with this title and could be considered a PBO.
41550 Judgment on Janus Andre Norton Sci-Fi 1969 c.1964; 1969;  Alex Schomburg listed as "complete and unabridged"
This edition is probably the 2nd ACE printing as well as a renumbering of old stock, as the cover art is the same and the spine end numbering is a white block with black numbers.
Judgment on Janus was originally published as ACE F-308 (1964).
41551 Judgement on Janus Andre Norton Sci-Fi 1972 c.1964; nd - probably 1972 Dean Ellis Title has an added "e" in title.
41552 Judgement on Janus Andre Norton Sci-Fi 1973 c.1964; 1972; 1973; Dean Ellis Title has an added "e" in title.
41553 Judgement on Janus Andre Norton Sci-Fi 1975 c.1964; 1972; 1973; 1975; Dean Ellis Title has an added "e" in title.
42032 -X A Judgment of Dragons Phyllis Gotlieb Sci-Fi 1985 1st ACE printing Nenad Lamut
42494 -5 K-9 Corps: Under Fire Kenneth Von Gunden Sci-Fi 1991 Second volume in this series.
42495 -3 K-9 Corps: Cry Wolf Kenneth Von Gunden Sci-Fi 1992 It appears that they finally got this series in the correct ACE Letter-Number sequence.  Third volume in this series.
42496 -1 K-9 Corps: Last Resort Kenneth Von Gunden Sci-Fi 1993
42801 -0 Kalin E. C. Tubb Sci-Fi 1978 c.1969; 1978; 2nd ACE printing John Schoenherr
42802 -9 Kalin: Dumarest of Terra #4 E. C. Tubb Sci-Fi 1982 c.1969; 1978; July 1982; 3rd ACE printing Paul Alexander Kalin was originally published in ACE Double 42800 (1969) bound with Alex Dain's The Bane of Kanthos.
43264 -6 Kedrigern in Wanderland John Morressy ACE Fantasy 1988 1st thus
43525 -4 Kensho Dennis Schmidt Sci-Fi 1979 1st ACE printing and PBO G. Benvenuti
43526 -2 Kensho Dennis Schmidt Sci-Fi 1981 c.1979; 1981; 2nd ACE printing
43527 -0 Kensho Dennis Schmidt Sci-Fi 1983 c.1979; 1981; 1986; 3rd ACE printing This is the sequel to Way-Farer (ACE 87625)
43607 -2 Ketch Rope C. R. Clumpner Western 1978
43671 Key Out Of Time Andre Norton Sci-Fi 1969 c.1963; 1969; 2nd ACE printing Ed Emschwiller listed as "complete and unabridged"
Interior illustration by Jack Gaughan
Key Out Of Time was originally published as ACE F-287 (1963).
43672 Key Out Of Time Andre Norton Sci-Fi 1972 c.1963; 1969; nd - but possibly 1972 W. Strudeski
43673 Key Out Of Time Andre Norton Sci-Fi 1973 c.1963; 1969; 1972; nd; W. Strudeski Possibly 1973 - based upon advertisements in back
43674 Key Out Of Time Andre Norton Sci-Fi 1975 c.1963; 1969; 1972; 1973 - but possibly 1976 W. Strudeski
43675 -5 Key Out Of Time Andre Norton Sci-Fi 1981 c.1963; 1969; 1972; 1973; 1976; 1981; 7th ACE printing Les Katz
43676 -5 Key Out Of Time Andre Norton Sci-Fi 1984 c.1963; 1969; 1972; 1973; 1976; 1981; 1984; 8th ACE printing Les Katz This ACE Letter-Number series was printed twice more with the same cover art, but different prices in December 1987 and May 1992.
43679 Key Out Of Time Andre Norton Sci-Fi 1992 c.1963; 1969; 1972; 1973l; 1976; 1981; 1984; 1987; 1992; nd Les Katz
43721 -8 The Keystone Kid Frank Roderus Western
43726 -5 Khi To Freedom Ardath Mayhar Sci-Fi 1993 1st ACE printing Stephen Hickman
43790 Kilkenny Louis L'Amour Western c.1954; 1963; nd; probably 3rd ACE printing Kilkenny was originally published as ACE D-574 (1954).
43791 Kilkenny Louis L'Amour Western c.1954; 1963; nd; Note the "Read Easy Large Type" header.  I also have a copy of ACE 43790 with the "Read Easy Large Type" header, suggesting that the edition control on this title may be another ACE headache (argh!).
44116 -5 Kill Ratio Janet Morris
and David Drake		 Sci-Fi 1987 1st ACE printing Michael Herring
44250 A Killer in Whiskey Smith Eric Smith
(aka: Eric Allen-Ballard)		 Western 1st ACE printing George Gross
44291 -9 Killer's Paradise Jack Bickham Western ACE/Charter edition Oh, how lazy ACE Books has gotten.  The cover art for Killer's Paradise is the same as for ACE 44250, they just severely cropped it for this cover.
44425 -3 Kilobyte Piers Anthony Sci-Fi 1994 c.1992; 1994; 1st ACE paperback printing Den Beauvais Originally released as an ACE/Putnam hardcover in 1993.
44453 -9 The Kingdom of the Cats Phyllis Gotlieb Sci-Fi 1985 1st ACE printing and PBO Sonja and Nenad Lamort
44464 -4 Kinch Matthew Braun Western c.1975; 1978; 1st ACE printing
44468 -7 King Dragon Andrew J. Offutt ACE Fantasy 1980 2nd ACE printing Rowena Morrill Interior illustrations by Estaban Maroto
44469 -5 King Dragon Andrew J. Offutt ACE Fantasy 1980 3rd ACE printing Rowena Morrill Interior illustrations by Estaban Maroto
44470 King Kong Edgar Wallace
and Merian C. Cooper		 Sci-Fi 1976 1st ACE printing Frank Frazetta This volume is a novelization by Delos W. Lovelace of the screenplay for the original King Kong (1933), one of the most popular horror films of that decade. Apparently released first in 1932 in a Grosset & Dunlap photoplay edition, this may be the first paperback edition of the novel.
There was a second printing of this ACE Letter-Number series with the same art and price.  The first printing has “The One, The Only | The Great Original” in silver foil lettering and one advertisement on the last page.  The second printing comes with “The Great Spellbinding Novel” in white lettering on the cover and the last page is blank.
44472 King Kong Lorenzo Semple, Jr. Sci-Fi 1977 1st ACE printing and PBO Frank Frazetta This is the complete script of the Dino de Laurentiis production of King Kong by Lorenzo Semple, Jr.
44481 -4 The King in Yellow Robert W. Chambers Horror 1977 c.1965; 1977; 2nd ACE printing Stephen Hickman The King in Yellow was originally published in ACE M-132 (1965). Collection of 10 horror stories in the genre of H. P. Lovecraft. This novel was also published in an abridged edition titled The Mask and Other Stories.
44485 King Kobold Christopher Stasheff Sci-Fi 1971 1st ACE printing Jack Gaughan
44488 -1 King Kobold Revived Christopher Stasheff Sci-Fi 1984 1st ACE printing Steve Hickman listed as "completely revised by the author"
The disclaimer on the frontis indicates that "portions of this book in a substantially different form were originally published under the title King Kobold." Hmmm - this is marked as the second book in the Warlock Series.
44489 King Kobold Revived Christopher Stasheff Sci-Fi nd Listed as "completely revised by the author."
44524 -1 King's Blood Four Sheri S. Tepper ACE Fantasy 1983 1st ACE printing and PBO James Christensen This volume was also reprinted in September 1983 with the same ACE Letter-Number series.
Book 1 of the True Game series.
44525 -X King's Blood Four Sheri S. Tepper ACE Fantasy 1984 c.1983; 1984; 3rd ACE printing James Christensen
44526 -8 King's Blood Four Sheri S. Tepper ACE Fantasy 1985 c.1983; 1984; 1985; 4th ACE printing James Christensen This volume was also reprinted in May 1989 with the same ACE Letter-Number series.
44851 -8 Kiteworld Keith Roberts Sci-Fi 1988 c.1985; 1986; 1988; 1st ACE printing and PBO Blas Gallego
44990 -5 Knave in Hand Laurence M. Janifer
(aka: Larry M. Harris)		 Sci-Fi 1979 1st ACE printing and PBO Sequel to Survivor.
This cover art is possibly attributed to Dean Ellis. In addition, this cover art was originally used for ACE 66780 (1976) - William Barton A Plague of All Cowards.
45000 Knave of Dreams Andre Norton Sci-Fi 1977 Charles Mikolaycak listed as "first paperback publication"
This edition appears to have had two (2) printing using the same ACE Letter-Number series.  The primary method to separate the printings is that the first has the address of 1120 Avenue of the Americas on the title page. The second has the ACE address as 360 Park Avenue South (where they moved in March to April 1978).
45001 Knave of Dreams Andre Norton Sci-Fi 1977 c.1975; 1977; nd; 2nd ACE printing Charles Mikolaycak
45001 -8 Knave of Dreams Andre Norton Sci-Fi 1980 c.1975; 1977; 1980; 3rd ACE printing Charles Mikolaycak Note: The checksum digit for the ISBN  -8, is not valid, should have been  -6.
45002 -4 Knave of Dreams Andre Norton Sci-Fi 1984 c.1975; 1977; 1980; 1984; Charles Mikolaycak Two items with this ACE Letter-Number volume.  The cover art by Charles Mikolaycak is no longer a wraparound and the background colour is changed. Secondly, although it is marked as 3rd edition, since the first edition had two printings, it is actually the 4th edition.
45125 -X The Knight and Knave of Swords Fritz Leiber Sci-Fi 1990 c.1988; February 1990; 1st ACE printing Darrell Sweet New tales of Gray Mouser and Fafhrd. 
45130 -6 Knight Life Peter David ACE Fantasy nd 2nd ACE printing
45131 -4 The Knight of the Swords Michael Moorcock ACE Fantasy 1987 c.1971; 1987; 1st ACE printing Robert Gould The Knight of the Swords was simultaneously published by Mayflower (UK) and Berkley (US)  in 1971 [with reprints].  It was later reissued by Berkley in 1986.
45346 -5 Koren Tim Lukeman ACE Fantasy 1982 1st ACE printing Sequel to Rajan.
45443 -9 The Aquiliad Somtow Sucharitkul ACE Fantasy 1983
45520 -4 The Kremlin Kill Nick Carter
(house pseudonym for Jack Canon)		 Spy Thriller 1984 1st ACE printing - Charter imprint Killmaster #193
46741 -5 Labyrinth of Night Allen Steele Sci-Fi 1992 Bob Eggleton
46850 Lady of the Bees Thomas Burnett Swann Sci-Fi 1976 1st ACE printing Stephen Hickman Lady of the Bees is an ACE Science Fiction Special #7.
46870 The Lad and the Lion Edgar Rice Burroughs Sci-Fi 1974 c. 1938; 1974; 1st ACE printing A shorter version of The Lad and the Lion was originally serialized in 1917.  The hardcover edition was in 1938, the Canaveral hardcover edition (which reprinted the 1938 ERB edition) was in 1964, and Ballantine Books published the first paperback edition in 1968. 
46871 The Lad and the Lion Edgar Rice Burroughs Sci-Fi 1976 c. 1938; 1974; 1976; 2nd ACE printing This edition, using the same ACE Letter-Number series, was reprinted two more times (August 1978 and June 1982). The differences can be determined by examining the ACE address on the title page.  The earlier printing of 46872-1 has the Avenue of the Americas address.  The August 1978 printing has the Park Avenue address (ACE Books moved in March to April of 1978).  In addition, the 1978 printing has the statement “Twenty-one thousand words added for book publication” but none of the other ACE printings have it and neither does the Ballantine edition. So this had to refer to the 1938 ERB hardcover edition being expanded from the 1917 serialized magazine printing.
46872 -1 The Lad and the Lion Edgar Rice Burroughs Sci-Fi 1982 c.1938; 1974; 1976; 1978; - probably 1982; 5th ACE printing This version does not have the publication statement found in the 1978 ACE edition.
46928 -0 Lady Slings The Blues Spider Robinson Sci-Fi 1992 1st ACE printing Richard Hescox
46929 -9 Lady Slings The Blues Spider Robinson Sci-Fi 1992 c.1992; 1992; 2nd ACE printing Richard Hescox
46941 -8 The Lady of the Snowmist Andrew J. Offutt ACE Fantasy 1984 1st ACE printing Volume three of the War of the Gods on Earth series.
46991 -4 Lake of the Sun Wynne Whiteford Sci-Fi 1989 1st ACE printing and PBO Don Dixon
46992 -2 Star Spawn Kenneth Von Gunden Sci-Fi 1990 1st ACE printing Another 'out-of-sequence' ACE Letter-Number series title.
46996 Land of Terror Edgar Rice Burroughs Sci-Fi 1973  c.1944; 1964; 1968; 1969; 1973; nd; 3rd ACE printing Frank Frazetta listed as "complete and unabridged"
Interior illustrations by Frank Frazetta
An "ACE Science Fiction Classic" on logo. This edition uses the same cover art as ACE F-256 (1964). Still not certain where this fits into with respect to printing history (see below).
46997 Land of Terror Edgar Rice Burroughs Sci-Fi 1973 c.1944; 1964; 1968; 1969; January 1973; 2nd ACE printing Frank Frazetta New cover art by Frank Frazetta
Land of Terror was originally published as F-256 (1964), G-737 (1968) and 04631 (1969).
Although the copyright page lists this as "second printing' the previous three editions [F-256 (1964), G-737 (1968) and 04631 (1969)] suggests that the attribution on this series is going to be complicated.  Thus, I will list them as 'printed edition' when documented, but the reader can easily compute which printing they really are.
46998 Land of Terror Edgar Rice Burroughs Sci-Fi 1974 c.1944; 1964; 1968; 1969; 1973; 1974; Frank Frazetta Furthermore, to complicate even the mess that is "Land of Terror" printing history, the following printings were issued with the same copyright page [January 1973 and 'second printing'].
46999 Land of Terror Edgar Rice Burroughs Sci-Fi 1976 c.1944; 1964; 1968; 1969; 1973; 1975/1976; Frank Frazetta
47000 -9 Land of Terror Edgar Rice Burroughs Sci-Fi 1978 c.1944; 1964; 1968; 1969; 1973, 1974; 1975/1976; 1978; 6th ACE printing Frank Frazetta There were two more printings of this ACE Letter-Number series (March 1980 and January 1982).
47001 -7 Land of Terror Edgar Rice Burroughs Sci-Fi 1982 c.1944; 1964; 1968; 1969; 1973, 1974; 1975/1976; 1978; 1980; 1982; April 1982; 9th ACE printing Frank Frazetta
47002 -5 Land of Terror Edgar Rice Burroughs Sci-Fi 1985 c.1944; 1964; 1968; 1969; 1973, 1974; 1975/1976; 1978; 1980; 1982; 1June 1985; 10th ACE printing Frank Frazetta
47011 The Land of Hidden Men Edgar Rice Burroughs Sci-Fi 1969 c.1963; 1969; 2nd ACE printing Roy Krenkel Jr. Original title: The Jungle Girl
Cover and title page illustration by Roy Krenkel Jr.
The Land of Hidden Men was originally published as ACE F-232 (1963).
Uses the same cover art and probably represents a re-use of old stock from the ACE F-232 editon.
47012 The Land of Hidden Men Edgar Rice Burroughs Sci-Fi 1973 c.1963; 1969; January 1973; 3rd ACE printing Frank Frazetta Original title: The Jungle Girl
47013 The Land of Hidden Men Edgar Rice Burroughs Sci-Fi nd c.1963; 1969; 1973; nd; 4th ACE printing Frank Frazetta Original title: The Jungle Girl
47016 -5 The Land of Hidden Men Edgar Rice Burroughs Sci-Fi 1978 c.1963; 1969; 1973; August 1978; 6th ACE printing Frank Frazetta Original title: The Jungle Girl
47020 The Land That Time Forgot Edgar Rice Burroughs Sci-Fi 1970 c.1963; August 1970; 2nd ACE printing Roy Krenkel Jr. An "ACE Science Fiction Classic" on logo. This edition is an example of renumbering of new old stock. Has the same cover art as ACE F-213 (1963).
47021 The Land That Time Forgot Edgar Rice Burroughs Sci-Fi 1973 c.1963; 1970; March 1973; 3rd ACE printing Frank Frazetta
47022 The Land That Time Forgot Edgar Rice Burroughs Sci-Fi nd c.1963; 1970; 1973; nd Frank Frazetta
47023 The Land That Time Forgot Edgar Rice Burroughs Sci-Fi nd c.1963; 1970; 1973; nd; Photo cover; Movie tie-in - This edition has a cover that is the one-sheet movie advertisement poster and the back cover includes images from the American International Pictures (AIP) release starring Doug McClure.
47024 The Land That Time Forgot Edgar Rice Burroughs Sci-Fi nd c.1963; 1970; 1973; nd; Plugs the movie on cover; same as ACE 47023
47025 -4 The Land That Time Forgot Edgar Rice Burroughs Sci-Fi 1979 c.1963; 1970 1973; 1979; New cover-art
47026 -2 The Land That Time Forgot Edgar Rice Burroughs Sci-Fi nd c.1963; 1970; 1973; 1979; nd; The last two editions of The Land That Time Forgot have a subheading of "A Novel Of Caspak" and the cover art uses the more modern (German U-boat) submarine image seen in the movie version covers.
47042 The Languages of Pao Jack Vance
(aka: John Holbrook Vance)		 Sci-Fi 1966 c.1966; nd; 3rd ACE printing Krusek
47055 The Last Best Friend George Sims Mystery 1967 1st ACE printing
47072 -6 The Last Castle Jack Vance
(aka: John Holbrook Vance)		 Sci-Fi 1977 c.1967; 1977; Rucker The Last Castle was originally published in ACE Double H-21 (1967) bound with Tony Russell Wayman's World of the Sleeper.
The Last Castle won the 1967 Nebula Award for best short novel and later the Hugo Award.
47073 -4 The Last Castle Jack Vance
(aka: John Holbrook Vance)		 Sci-Fi 1982 c.1967; 1977; 1982; 5th ACE printing R. Courtney
47075 -0 The Last Coin James P. Blaylock ACE Fantasy 1989 c.1988; 1989; 1st ACE mass market printing James Gurney
47080 -7 The Last Days of Wolf Garnett Clifton Adams Western c.1970; 1973; nd;
47081 The Last Days of Wolf Garnett Clifton Adams Western c.1970; August 1973; 1st ACE printing
47082 -3 The Last Days of Wolf Garnett Clifton Adams Western c.1970; 1973; nd; The Last Days of Wolf Garnett was a "Spur Award" winner for "Best Western Novel."
47090 ? Ray Hogan Western c.1963;
47121 -8 The Last Knight of Albion Peter Hanratty ACE Fantasy 1987 King Arthur
This imprint is the "ACE New Infinities" logo.
47161 The Last Planet Andre Norton Sci-Fi 1969 c.1955; 1969; Harry Barton  listed as "complete and unabridged"
Original title: Star Rangers
The Last Planet was originally published in ACE Double D-96 (1955) bound with Alan E. Nourse's A Man Obsessed. It was also released as an ACE Special Edition (single) D-96 (1955) and reprinted in ACE F-366 (nd). All of these editions use the same cover art. In this edition, the art is cropped.
47162 The Last Planet Andre Norton Sci-Fi nd c.1955; 1969; nd Dean Ellis Original title: Star Rangers
47163 The Last Planet Andre Norton Sci-Fi 1974 c.1955; 1969; April 1974; 7th ACE printing Dean Ellis Original title: Star Rangers
47183 -8 The Last Samurai Nick Carter Spy Thriller nd 1st ACE printing - Charter imprint George Gross
47201 Last Stand Mesa L. L. Foreman Western 1969
47401 The Languages of Pao Jack Vance
(aka: John Holbrook Vance)		 Sci-Fi nd c. 1957; 1958; 1966; nd; 2nd ACE printing Gray Morrow
listed as "complete and unabridged"
Cover and title page by Gray Morrow
This edition uses the same Gray Morrow cover art from ACE F-390 (1966).
Notice that the five-digit numbering sequence for this volume is a bit out of place (see ACE 47042). Is this an error in the printing such that it should be listed as 47041.
47420 -9 The Lavalite World Philip Jose Farmer Sci-Fi 1977 1st ACE printing Boris Vallejo listed as "first publication in any form"
The fifth volume of the "World of Tiers" series.
47440 Lavender-Green Magic Andre Norton Sci-Fi 1977 1st ACE printing Charles Mikolaycak Interior illustrations and frontspiece by Judith Gwynn Brown
Originally published by Crowell in 1974, this copy is listed as "First time in paperback" on the front cover. The artwork is not credited on the front matter but is signed on the back cover as "Mikolaycak (c) 76-9."
47441 Lavender-Green Magic Andre Norton Sci-Fi 1980 c.1977; 1980; 2nd ACE printing Charles Mikolaycak This edition is “A Tempo Star Book | Distributed by Ace Books”.
Interior illustrations and frontspiece by Judith Gwynn Brown
47442 -X Lavender-Green Magic Andre Norton Sci-Fi 1982 c.1977; 1980; 1982; 3rd ACE printing Charles Mikolaycak Interior illustrations and frontspiece by Judith Gwynn Brown
47493 -4 Law Man Lee Leighton Western c.1953; nd; ACE Charter edition George Gross
47500 Law of the Trigger Giles A. Lutz Western c.1959; nd;
47501 -9 Law of the Trigger Giles A. Lutz Western c.1959; 1986; ACE Charter edition Law of the Trigger was originally published as ACE Double D-408 (1959) bound with Edwin Booth's Wyoming Welcome.
47510 Law of the Lawless Wayne C. Lee Western 1977 1st ACE printing
47521 -3 The Lazarus Effect Frank Herbert
and Bill Ransom		 Sci-Fi 1987 Sequel to The Jesus Incident.
47800 The Left Hand of Darkness Ursula K. Le Guin Sci-Fi 1969 1st ACE printing and PBO Leo and Diane Dillon This is an ACE Science Fiction Special (1st series). This story won both the Hugo Award and the Nebula Award. When this happened, ACE Books released it with a cover blurb announcing the awards. However, they used the same cover art as well as the same five-digit number (let's make things confusing for the cataloguers). This volume was published April 1971 per Stewart Wells reference.
The Left Hand of Darkness was originally published as ACE Science Fiction Special (1st series) ACE 47800 in March 1969.
47800 -8 The Left Hand of Darkness Ursula K. Le Guin Sci-Fi 1972 c.1969; 1972; 2nd ACE printing Josh Kirby The 3rd (April 1973) and 4th (June 1973) printings use the same ACE Letter-Number series (47008-8).
47801 The Left Hand of Darkness Ursula K. Le Guin Sci-Fi 1974 c.1969; 1972; May 1974 Josh Kirby
47802 The Left Hand of Darkness Ursula K. Le Guin Sci-Fi 1974 c.1969; 1972; 1974; 1974; 7th ACE printing Alex Ebel
47803 The Left Hand of Darkness Ursula K. Le Guin Sci-Fi 1975 c.1969; 1972; 1974; 1975; 8th ACE printing Alex Ebel
47804 The Left Hand of Darkness Ursula K. Le Guin Sci-Fi 1976 c.1969; 1972; 1974; 1975; 1976; 11th ACE printing Alex Ebel
47805 The Left Hand of Darkness Ursula K. Le Guin Sci-Fi 1976 c.1969; 1972; 1974; 1975; 1976, 13th ACE printing Alex Ebel The ACE Letter-Number series 47805 was used for the 12th printing (July 1976) and appears to continue being used (13th; December 1976, 14th; June 1977; 15th; June 1978, 16th; November 1978, and 17th; April 1979) until the 18th printing (in January 1980).
Based upon the cover note, this volume contains "A new and never-before published introductory essay by the author commissioned especially for this edition."
47806 -9 The Left Hand of Darkness Ursula K. Le Guin Sci-Fi 1981 c.1969; 1972; 1974; 1975; 1976, 1981; 21st ACE printing Alex Ebel Note: The 20th printing has the same ACE letter-number series as well as price.  This is possibly the same for the 19th printing, but the 18th printing (January 1980) uses a different ACE letter-number series and has a lower price.  Thank you Bill for the details.
47807 -7 The Left Hand of Darkness Ursula K. Le Guin Sci-Fi nd c.1969; 1972; 1974; 1975; 1976, 1981; nd
47809 -3 The Left Hand of Darkness Ursula K. Le Guin Sci-Fi nd c.1969; 1972; 1974; 1975; 1976, 1981; nd
47850 -6 Legacy James H. Schmitz Sci-Fi 1979 1st ACE printing Bob Adragna Original title: A Tale of Two Clocks
47851 -4 Legacy James H. Schmitz Sci-Fi nd c.1979; nd Bob Adragna Original title: A Tale of Two Clocks
47951 The Legend of Blackjack Sam Lee Hoffman Western c.1966; nd; probably 2nd ACE printing Gerald McConnell
47952 The Legend of Blackjack Sam Lee Hoffman Western c.1966; nd; Gerald McConnell The Legend of Blackjack Sam was originally published as ACE F-380 (1966).
47962 -6 Legend of the Duelist Rutledge Etheridge Sci-Fi 1993 1st ACE printing Luis Royo There is another (at least one) reprint of this title with the same ACE Letter-Number series, no date and same price on cover.
48040 -3 Legion of the Damned William C. Dietz Sci-Fi 1993 1st ACE printing and PBO Bruce Jensen Numerous reprinting of this title using the same ACE Letter-Number series, with no dates.
48180 -9 Liavek Will Shetterly
and Emma Bull (eds.)		 ACE Fantasy 1985 1st ACE printing and PBO
48191 -4 Liavek: Spells of Binding Will Shetterly
and Emma Bull (eds.)		 Sci-Fi 1988 D.K.S. A collection of short stories in a shared fantasy universe.
Includes: Riding the Hammer (John M. Ford), Portrait of Vengeance (Kara Dalkey), The Skin and Knife Game (Lee Barwood and Charles de Lint), Strings Attached (Nathan A. Bucklin), The Last Part of the Tragical History of Acrilat (Pamela Dean), Mad God (Patricia C. Wrede), The Tale of the Stuffed Levar (Jane Yolen),  An Act of Love (Steven Brust, Gregory Frost and Megan Lindholm) and Spells of Binding (poem by Pamela Dean).
48232 -5 Life Among The Asteroids Jerry Pournelle
with John F. Carr (eds.)		 Sci-Fi 1992 1st ACE printing Richard Courtney Volume IV of The Endless Frontier. Short story collection on theme of "life among the asteroids."
48312 -7 Light Raid Connie Willis Sci-Fi 1990 1st ACE edition John Harris The reprint ACE Letter-Number edition in 1996 has the same copyright page, with the same notation of the artwork by Harris, but the cover art for this edition is not by Harris.  ACE strikes again.
48335 -6 Lilac Night Michael T. Hinkemeyer Mystery 1982 1st ACE printing
48358 -5 The Limbreth Gate Megan Lindholm ACE Fantasy 1984 1st ACE printing
48421 -2 The Lincoln Hunters Wilson Tucker Sci-Fi 1977 2nd ACE printing Davis Meltzer Original cover art by Davis Meltzer for The Lincoln Hunters. Acrylic on board; 7" x 11." Another story that was influential in my course of study and interests.
48433 -6 The Lion Game James H. Schmitz Sci-Fi 1982 1st ACE printing Wayne Barlowe Includes Goblin Night, Sleep No More, and The Lion Game.
Note that the cover has Wayne Barlowe's signature initals [WB inside a square] on the lower right margin, but the cover art is credited to Steve Durke. The other thing to note is that the cover blurb on ACE 48433-6 says "A Telzey Amberdon Adventure" whereas ACE 48434-4 has "The Third Telzey Amberdon Adventure."
48434 -4 The Lion Game James H. Schmitz Sci-Fi 1985 c.1973; 1982; January 1985; 2nd ACE printing Wayne Barlowe Includes Goblin Night, Sleep No More, and The Lion Game.
48490 Little Fuzzy H. Beam Piper Sci-Fi 1976 c.1962, 1976; Michael Whelan Little Fuzzy was originally published by Avon Books (1962) and although the Whelan cover art is great, the Avon cover art was even better. - Dr. Smith
48492 -1 Little Fuzzy H. Beam Piper Sci-Fi 1978 c.1962, 1976; 1978; Michael Whelan
48494 -0 Little Fuzzy H. Beam Piper Sci-Fi nd c.1962; 1976; 1978; nd; Michael Whelan
48497 -2 Little Fuzzy H. Beam Piper Sci-Fi 1984 c.1962; 1976; 1978; 1984; 11th ACE printing Michael Whelan
48499 -9 Little Myth Marker Robert Asprin ACE Fantasy 1987 Walter Velez
48541 -3 Living Death Nick Carter
(house pseudonym for Jon Messmann)		 Spy Thriller 1982 1st ACE printing - Charter imprint
48877 The Lonely Ride Giles A. Lutz Western c.1971; 1973; 1st ACE printing George Gross
48879 -X The Lonely Ride Giles A. Lutz Western c.1971; 1973; nd; 2nd ACE printing Different cover art. Artist name (Carl ?) is cut off on the image.
48918 Long Run Nelson Nye Western c.1959; nd;
48920 -6 Long Run Nelson Nye Western c.1959; 1976; nd; George Gross
48921 Long Run Nelson Nye Western 1976 c.1959; 1976; George Gross
48922 -2 The Long Way Home Poul anderson Sci-Fi 1978 Michael Whelan The Long Way Home was expanded from No World of Their Own (1955). No World of Their Own was originally published in ACE Double D-110 (1955) bound with Isaac Asimov's 1,000 Year Plan. No World of Their Own was also published as ACE D-550 (1962).
48923 -0 The Long Way Home Poul anderson Sci-Fi 1979 c.1978; 1979; Michael Whelan
48924 -9 The Long Way Home Poul anderson Sci-Fi 1981 c.1978; 1979; May 1981; and December 1981; Michael Whelan
48925 -7 Long Run Nelson Nye Western c.1959; 1976; ACE Charter edition
possibly 1986		 George Gross Long Run was a "Spur Award" winner for "Best Western Novel."
48926 -8 The Long Way North Jim Bosworth Western c.1964; nd; 2nd ACE printing The Long Way North was originally published as ACE F-286 (1964).
48928 -1 The Long Twilight Keith Laumer Sci-Fi 1986 Bruce Jensen
48970 Looking Backward: From the Year 2000 Mack Reynolds
(aka: Dallas McCord Reynolds)		 Sci-Fi 1973 1st ACE printing J. H. Breslow
48990 Look Back On Murder Doris Mile Disney Mystery 1976 c.1951; 1976; 1st ACE printing
49051 -4 Lord Kalvan of Otherwhen H. Beam Piper Sci-Fi nd c.1965; nd Michael Whelan Lord Kalvan of Otherwhen was originally published as ACE F-342 (1965).
49052 -2 Lord Kalvan of Otherwhen H. Beam Piper Sci-Fi 1978 c.1965; nd; late 1977/early 1978 Michael Whelan
49055 -7 Lord Kalvan of Otherwhen H. Beam Piper Sci-Fi 1984 c.1965; 1977/1978; 1984; 6th ACE printing Michael Whelan
49141 -3 Lord Darcy Investigates Randall Garrett Sci-Fi 1981 1st ACE printing
49142 -1 Lord Darcy Investigates Randall Garrett Sci-Fi nd c.1981; nd;
49236 Lord of Thunder Andre Norton Sci-Fi nd c.1963; 1968; nd; probably 3rd ACE printing Alex Schomberg This ACE Letter-Number was catalog printed twice. Neither are dated nor is there a number line. The first printing was likely 1970 and has no advertisements in the back. The second printed in December 1971 [per Stuart Wells] and has one advertisement.
Lord of Thunder was originally published as ACE F-248 (1963) and ACE G-691 (1968) with the same Alex Schomberg cover art.
49237 Lord of Thunder Andre Norton Sci-Fi nd c.1963; nd; Alex Schomberg
49252 -5 Lord of the Trees and The Mad Goblin Philip Jose Farmer Sci-Fi 1980 c.1970; 1980; This is an ACE Single with two stories that were originally published as ACE Double 51375 (September 1970).  This volume was also reprinted with the same ACE Letter-Number series and the publication date of May 1980 (this printing number line ends with a '3' and is likely early 1981).
49255 -X Lord Tedric # 1 Gordon Eklund ACE Fantasy 1978 1st ACE printing Gray Morrow Fantasy series based upon an idea conceived by E. E. "Doc" Smith.  On the first page of the ACE edition there is a little more: “Before he died, E. E. Doc Smith, creator of the famous Lensman and Skylark series, developed the outline and plot for an exciting new space adventure, the LORD TEDRIC series.” This is the first volume of this series.
Originally published by Baronet in 1978 as a trade-sized edition. Same cover as the ACE paperback by Gray Morrow.
49256 -8 Lord Tedric #3: Black Knight of the Iron Sphere Gordon Eklund ACE Fantasy 1981 1st ACE printing
49291 The Lost Continent Edgar Rice Burroughs Sci-Fi 1969  c.1963; 1969; 2nd ACE printing Frank Frazetta Original title: Beyond Thirty
Cover and title page by Frank Frazetta
The Lost Continent was originally published as ACE F-235 (1963) with the "Science Fiction Classic logo." This edition uses the same Frazetta cover art with the same "Science Fiction Classic logo."
49292 The Lost Continent Edgar Rice Burroughs Sci-Fi 1973 c.1963; 1969; 1973; 3rd ACE printing Frank Frazetta Original title: Beyond Thirty
This edition (and those later) have lost the interior art that was found in ACE 49291 and ACE F-235.
49293 The Lost Continent Edgar Rice Burroughs Sci-Fi 1974 c.1963; 1969; 1973; 1974; 4th ACE printing Frank Frazetta Original title: Beyond Thirty
49294 The Lost Continent Edgar Rice Burroughs Sci-Fi 1975 c.1963; 1969; 1973; 1974; 1975; 5th ACE printing Frank Frazetta Original title: Beyond Thirty
49295 The Lost Continent Edgar Rice Burroughs Sci-Fi 1976 c.1963; 1969; 1973; 1974; 1975; 1976; 6th ACE printing Frank Frazetta Original title: Beyond Thirty
49296 -7 The Lost Continent Edgar Rice Burroughs Sci-Fi 1979 c.1963; 1969; 1973; 1974; 1975; 1976; 1979; 7th ACE printing Sanjulian Original title: Beyond Thirty
49299 -1 Lost Dorsai Gordon R. Dickson Sci-Fi 1980 1st ACE printing Enric Interior illustrations by Fernando Fernandez
49300 -9 Lost Dorsai Gordon R. Dickson Sci-Fi 1980 c.1980; see notes Enric Interior illustrations by Fernando Fernandez
Published at least three times with the same ACE Letter-Number and price: October 1981, August 1982, and March 1983. The first two have the slug line “A 1980 Nebula Nominee,” but the 1983 printing changes that to “Hugo & Nebula Award Winner.”
49302 -5 Lost Dorsai Gordon R. Dickson Sci-Fi 1985 c.1980; 1985; 6th ACE printing Enric Interior illustrations by Fernando Fernandez
49303 -3 Lost Dorsai Gordon R. Dickson Sci-Fi nd c.1980; 1985; nd; 7th ACE printing Enric Interior illustrations by Fernando Fernandez
49492 -7 Lost Souls Greg Bear Sci-Fi 1982 c.1979; 1982; 1st thus under this title and as an ACE Charter edition
This is a re-naming of Greg Bear's Psychlone, originally published in ACE 68790-3.
49500 Lost on Venus Edgar Rice Burroughs Sci-Fi 1969 c.1935; 1963; 1969; 2nd ACE printing Frank Frazetta Lost on Venus was originally published as ACE F-221 (1963).
On these two edition, there is an "ACE Science Fiction Classic" on the logo. These edition use the same cover art as ACE F-221 (1963) and may represent the re-use of new old stock.
49501 Lost on Venus Edgar Rice Burroughs Sci-Fi 1969 c.1935; 1963; 1969; 3rd ACE printing Frank Frazetta
49502 Lost on Venus Edgar Rice Burroughs Sci-Fi 1973 c.1935; 1963; 1969; 1973; 4th ACE printing Frank Frazetta This edition, and later editions, lose the "ACE Science Fiction Classic" on the logo.
49503 Lost on Venus Edgar Rice Burroughs Sci-Fi 1974 c.1935; 1963; 1974; 5th ACE printing Frank Frazetta
49504 Lost on Venus Edgar Rice Burroughs Sci-Fi nd c.1935; 1963; nd; Frank Frazetta
49505 Lost on Venus Edgar Rice Burroughs Sci-Fi nd c.1935; 1963; nd; Frank Frazetta
49506 -0 Lost on Venus Edgar Rice Burroughs Sci-Fi 1979 c.1935; 1963; 1979; 8th ACE printing Esteban Moroto
49507 -9 Lost on Venus Edgar Rice Burroughs Sci-Fi nd c.1935; 1963; 1979; nd; Esteban Moroto
49515 -X The Lost Valley of Iskander Robert E. Howard Sci-Fi 1986 1st ACE printing Ken Kelly ACE Charter edition
49525 -7 A Lost Tale Dale Estey ACE Fantasy 1986 ACE fantasy mystery?
49535 -4 The Lost Traveller Steve Wilson Sci-Fi 1978
49548 -6 Love Conquers All Fred Saberhagen Sci-Fi 1979 1st ACE printing Bob Adragna This novel originally appeared in the November (1974), December (1974), and January (1975) issues of Galaxy Magazine.
49851 -5 Orbital Decay Allen Steele Sci-Fi 1989 1st ACE printing Romas Kukalis "Step Back" covers and interior illustrations by Romas Kukalis
This volume is certainly outside of the ACE Letter-Number series coding.
The cover art for this volume is another publishing gimmick - the "cut out" cover or "step back art."  The idea of a "cut out" on the cover, which only partially exposes another full image underneath, essentially teasing the readers into picking up and opening the book just to see what was underneath.
Original cover art for Orbital Decay by Romas Kukalis.  The first cover is the underlying artwork that was only partially exposed due to the 'cut out.'  Acrylic on masonite, 30" x 18" and signed. The second cover is the top portion of the dual 'cut out' cover art.  Acrylic on masonite, 30" x 18" and signed.
49972 -4 Lord Kelvin's Machine James P. Blaylock Sci-Fi 1992 1st ACE printing Jim Thiesen