Many of the key cultural and technological concepts introduced in this series were incorporated into the role-playing game “Traveller”, including its name (which used the British spelling of the word with two "L"s). “Traveler” is the series’ ubiquitous term for those who wander the stars in search of fortune, adventure, or whatever motivates them (in Duamrest’s case, the search for his homeworld, Earth).
While the notion of radically varied levels of technological sophistication between planets is certainly not unique to the Dumarest novels, it is highly significant in the series, as it is in the game. The central role of “free traders” (small, independently owned and operated merchant starships, often speculatively investing in their cargos in the hope of finding a lucrative market, and carrying commissioned cargo and paying passengers when available) is common to the series and the game as well.
The game's concept of High, Middle and Low passages originated here. High passage is expensive and relatively luxurious, Middle is a working passage as a temporary member of the crew and Low passage is a berth in a cryogenic tank, cheap but fraught with health risks (including a 15% death rate). As there is no universally recognized currency, items of value are often described in terms of how many High passages they are worth, and travelers performing valuable (and usually dangerous) services are often paid in kind.
In the series, quicktime is a drug which slows perception and metabolism so that time seems to pass 40 times more quickly to the observer. This is usually given to passengers traveling High (and often to the starship crews as well) to alleviate the boredom of long interstellar journeys. Quicktime’s counterpart is slowtime, which accelerates perception and metabolism so that the user lives at 40 times the usual rate. This is usually given to medical patients along with intravenous feeding and induced unconsciousness to speed the healing process, but can also be used by conscious individuals to do more than would be humanly possible in a brief period of time. This is highly risky, but sometimes essential (e.g. for emergency repairs when the engine is damaged and will blow up in an hour, but will take a day to fix). These became the “fast” and “slow” drugs in Traveller.
The seemingly incongruous but common preference for edged weapons (especially knives) for self-defense among travelers also carried into the game to some degree. This actually makes a great deal of sense in the fragmented galactic culture of the novels, because the prospect of finding ammunition for a projectile weapon made halfway across the galaxy is slim to none, and few travelers have enough disposable income to have ammo custom-made on a regular basis. (And yes, as long as ammo is available, imparting a lethal dose of kinetic energy into an opponent from a distance is still one of the safest, cheapest and most effective ways to kill them, even in the distant future). To a lesser degree the same is true of lasers; finding a compatible power source to replace or recharge an expended one would be costly and time-consuming (not to mention that lasers are among the most expensive self-defense options to acquire in the first place).