Second Variety - novelette by Philip K. Dick
Youth - novelette by Isaac Asimov
To Each His Star - short story by Bryce Walton
Security - novelette by Poul Anderson
Divinity - short story by William Morrison
The Hour of Battle - short story by Robert Sheckley
Instant of Decision - novelette by Randall Garrett
Let 'em Breathe Space! - novelette by Lester del Rey (variant of Let 'em Breathe Space)
The Ultroom Error - short story by Jerry Sohl (variant of Ultroom Error)
Infinite Intruder - novelette by Alan E. Nourse
Collectivum - short story by Mike Lewis
The Adventurer - short story by C. M. Kornbluth
Decision - short story by Frank M. Robinson
Pursuit - novelette by Lester del Rey
Exile - short story by H. B. Fyfe
Stop Look and Dig - short fiction by George O. Smith (variant of Stop, Look and Dig)
The Worshippers - novelette by Damon Knight
The Hunters - short story by William Morrison
The Ego Machine - novelette by Henry Kuttner and C. L. Moore [as by Henry Kuttner]
The Variable Man - novella by Philip K. Dick
Ullr Uprising - novel by H. Beam Piper