Editing Ringworld (section)

==Concepts reused==
In addition to the two aliens, Niven includes a number of concepts from his other Known Space stories:

* The puppeteers' [[General Products (Larry Niven)|General Products hulls]], which are impervious to any known force except [[visible light]] and [[gravity]], and for a long time thought indestructible by anything except [[antimatter]]. The ''Fleet of Worlds'' prequels reveal two other ways that the hulls can be destroyed. 
* The [[Slaver stasis field]], which causes time in the enclosed volume to stand still; since time has for all intents and purposes ceased for an object in [[Stasis (fiction)|stasis]], no harm can come to anything within the field.
* The idea that [[luck]] is a [[genetics|genetic]] trait that can be strengthened by [[selective breeding]].
* The tasp, a device that remotely stimulates the [[pleasure center]] of the [[brain]]; it temporarily incapacitates its target and is extremely psychologically addictive. If the subject cannot, for whatever reason, get access to the device, intense depression can result, often to the point of madness or suicide. To use a tasp on someone from hiding, relieving them of their anger or depression, is called "making their day".
* [[Boosterspice]], a drug that restores or indefinitely preserves youth.
* Scrith, the metal-like substance of which the ''Ringworld'' is built (and presumably the shadow squares and wires too), that has a [[tensile strength]] nearly equal in magnitude to the [[Strong interaction|strong nuclear force]] making it similar to the concept of [[nuclear matter]]. This makes it an example of [[Unobtainium#Science fiction|unobtainium]]. This is similar to the Pak Protector's "twing" used in other Larry Niven stories.
* Impact armor, a flexible form of clothing that hardens instantly into a rigid form stronger than steel when rapidly deformed, similar to [[Ballistic vest#Nanomaterials in ballistics|certain types of bulletproof vests]].
* The hyperspace shunt, an engine for faster-than-light travel, but slow enough (1&nbsp;[[light-year]] per 3&nbsp;days, ~122&nbsp;[[Proper velocity|''c'']]) to keep the galaxy vast and unknown; the new "quantum&nbsp;II hyperspace shunt", developed by the Puppeteers but not yet released to humans, can cross a light-year in just 1.25&nbsp;minutes (~421&nbsp;000&nbsp;[[Proper velocity|''c'']]).
* Point-to-point teleportation at the speed of light is possible with [[transfer booth]]s (on Earth) and [[stepping disk]]s (on the Puppeteer homeworld); on Earth, people's sense of place and global position has been lost due to instantaneous travel; cities and cultures have blended together.
* A theme well covered in the novel is that of cultures suffering technological breakdowns who then proceed to revert to belief systems along [[religion|religious]] lines. Most ''Ringworld'' societies have forgotten that they live on an artificial structure, and now attribute the phenomena and origin of their world to divine power.