Science Fiction Vs Fantasy

Basic Information

Defining and dividing Science Fiction from Fantasy (and vice-versa) is very tricky and subjective, hence the need for the encompassing category of Speculative Fiction. Here's a small compare and contrast list that might help, or might just annoy you…

Science Fiction	Fantasy
Improbable	Impossible
The Future	The Past
Spacecraft	Horse
Aliens	Five Races, Mythological Creatures
Starfish Aliens	Dragons
Genetic Engineering, Psionics, Radiation, Robotics, Technology	Magic
Mad Scientist, Psychic Powers	Wizard
Robot	Elemental, Golem
Laser	Sword
Outer Space, Interstellar Terrain	Standard Fantasy Setting
Negative Space Wedgie	Monster of The Week
Planet of Hats	Adventure Towns
Abusive Precursors	Orcus On His Throne
Starship Captian	Knight In Shining Armor
Sufficiently Advanced Technology, Sufficiently Advanced Aliens	Magic A is Magic A, Magitek

Sources

Bibliography

1. TV Tropes Wiki

2. What's New with Phil and Dixie: Medieval vs. SF page 1 — a classic take on this question. ( Page 2 )

Game and Story Use

• Naturally ripe for subversion or crossover genres - sci-fi with swords is not unknown and quite a few fantasy settings include various degrees of precursors with some decidedly ambiguous leftovers.
• Confusingly the term "science fantasy" is sometimes employed to describe the works also known as "space opera" and similar things where a thin coat of high technology paint has been splashed over what is clearly a fantasy setting - usually featuring (space) knights, (laser) swords and (space) magic and with no real attempt to integrate any kind of technological or engineering basis.