Sourcebook for GURPS. Backcover blurb excerpt:

"Play out thrilling adventures from science fiction's Golen Age in the 'Viagens Interplanetarias' setting of L. Sprague de Camp's stories set on the planet Krishna!

The natives are all too human--except for the green skin, the feathery antennae, the eggs...'Protected' from technology by interstellar law, armored knights clash in a wilderness of blue woods while square-rigged war galleys patrol the inland seas. It will take a quick sword and quicker wits if a visitor is to survive:

Tailed beastmen of the Koloft Swamp!
Ferocious six-legged yekis!
The dread pirates of a floating island!
Sacrificial rites within an ancient tower!
Tentacled sea-monsters!
Barbarian hordes sweeping out of the desert!
Buxom green-skinned princesses and eccentric kings!

Discover space adventure the way it ought to be!"