Ace Double (#11650) February 1973 paperback. Condition is VG+: tight and almost square, spine has 2 OR 3 faint lines; tape-reinforced corners on COMPUTER WAR side (and small chip on other side where corners were not reinforced); age tanning is very mild and uniform. Bookstore sticker and small pen-mark inside cover on CODE DUELLO side; no other marks, stamps or writing .

An Ace Double from 1973, containing Code Duello and Computer War - both by Mack Reynolds. Each side states "2nd printing" and gives dates for original appearance - those dates don't match because each of these books was originally paired (in Ace Doubles) with a different book by another author.

Code Duello (183 pages, cover by Kelly Freas; copyright 1968.) Section G of United Planets is running out of trained agents, so they start using "special talents": a research biologist who could bend steel bars like rubber bands, a middle-aged lady with total recall, a lady acrobat who looked like an 8-year old, a bullwhip artist, a mild mannered young man who'd never lost a bet in his life, and the best pickpocket who ever lived. They are assigned to the frontier planet Firenze, where citizens are always ready to defend their honor, under the Code Duello.

Computer War (133 pages, cover by Ed Valigursky; copyright 1967.) This appeared in 1967 as a serial in Analog magazine. Alphaland's computers predict that a 2.35 month war will conquer rival nation Betastan, or else the economy of Alphaland will fail. The Betastanis invest in high-tech, not machinery of war.