How do you handle communication in science fiction? Ship to ship, planet to planet, etc.

Do you try to keep it "realistic" and restrict communication to the speed of light, which could mean a lag of minutes or hours or longer within a star system, and forget calling back to HQ on earth for instructions or reporting when you are light years away.

Or do you handwave some means of instant communication over Interstellar distances?

What has worked for you and what hasn't?

Depends on the setting assumptions.

I prefer courier ships.  Information travels at the same rate that ships move between star systems. 

FTL comms means you can just call your boss to get instructions when you need them.  That actually means you lose your own power to make a call on the spot.  If you can call, you should call, and you will call.  And that really means that some desk jockey is in charge, not you.

No.  If given a choice, I prefer when the people on scene have to be the ones to decide how to proceed with resolving the local issues.  This puts the burden of performance squarely and solely on the players.  They're playing without a safety net.

In other words, it's their game, not HQ's.

The only sci fi I've stuck with has been Traveller, which assumes faster than light starship travel but no faster than light comms except by courier. Works pretty well. "Local problem solver/agent on the scene" makes for good adventures, so I don't see that there's any loss to it.

Quote from: Joey2k on February 21, 2025, 07:55:25 PMHow do you handle communication in science fiction? Ship to ship, planet to planet, etc.

Do you try to keep it "realistic" and restrict communication to the speed of light, which could mean a lag of minutes or hours or longer within a star system, and forget calling back to HQ on earth for instructions or reporting when you are light years away.

Or do you handwave some means of instant communication over Interstellar distances?

What has worked for you and what hasn't?

Quote from: jeff37923 on February 21, 2025, 08:03:36 PMDepends on the setting assumptions.

I usually go with the setting assumption.

But I do like the idea of mixing tech. In real life we don't have just one mode of transportation. We have lots that are suited to specific uses. Cargo ships, jet airliner, bicyles.
FTL transport and communication could be a mix as well. Instant FTL communication could be extremely expensisve and have other limitations, like "warp storms" that garble the comm. Couriers would be less expensive, more reliable, but slower. Stuff like that.
Even FTL travel itself. I really like the idea of a setting with mixed tech. Stargates, warp drives, hyperspace. Each with it's own advantages and drawbacks.

The only two scifi settings with interstellar travel I've run/played in are Star Trek (Dominion War aftermath period) and Battletech.

The Dominion War aftermath makes for an interesting situation for communications. Subspace radio is a thing, but without booster array satellites the real-time range is fairly limited.

I decided that such satellites were a priority target during the war (disrupting command and control is a vital tool in crushing an enemy) and so, in the immediate aftermath only high priority routes (ex. Earth to DS9 and between the capitols of the great powers) have real-time communications; the rest is limited to unboosted speeds that range from real-time (within the same system) to minutes, hours, and rarely days (typically a spoke like DS9 is within less than a day for radio which can relay it to another point on a spoke instantly and retransmit from there).

It was a good way to have instant when needed and not instant at other times.

Battletech basically has its Hyperpulse generators that can transmit information between points in one direction instantly, but requires alignment with another HPG to do it... which typically requires a set schedule of synchronizing making it more like a mail service for all but the most priority routes.

In my own system theres three methids.
In system radio is used and there is the usual time delay. So if the ship were out at the orbit of say planet Pluto, then that is about four and a half hours.

Interstellar communication before FTL comms were discovered were via small unmanned hyperspace message capsules that could hard burn under FTL to another system in a couple of months. Prior to drive improvements the same trip would have taken hundreds of years as FTL was still relatively slow and habitable worlds few and very far between.

With the advent of a sort of hyperspace shortcut interstellar travel and comm time was shortened from months to minutes. Does not work in system though and neither does the hyperspace engine.

GURPS: Space has got the best section on communications I've found.

Quote from: GURPS: SpaceCOMMUNICATIONS

Stellar nations are almost impossible to maintain over great distances without
some sort of FTL communication, whether by "radio" or by courier ship. When the
message lag between the capital and its frontiers is measured in months, the state is
likely to break up, or at least abandon central government. If the campaign takes
place in a large area relative to the speed of communication, there will be many stellar governments. If FTL communication exists, then larger areas can be governed –
though FTL travel is still necessary for truly large empires.

If ships can cross the nation in a month, and FTL radio messages in a day, then it
hardly matters whether the nation is 10 parsecs across or 1,000 (except that the latter
allows a lot more room to hide!). The speeds of ship travel and "radio" communications (if any), relative to the size of the area to be traveled, will shape your interstellar culture.

Any organization with a monopoly on FTL communications will have a great
deal of power – perhaps even enough to control the government.

No FTL Radio-

At this stage, the speed of communications is that of the fastest starship. Fast
courier ships will maintain contact between worlds, carrying mail, news, and government dispatches. Slower, independent ships – often those of free traders – contract for mail runs between less important worlds. The "Communications Fleet" is a
vital branch of interstellar government. Without its services, communication – and
perhaps even the nation itself – would soon break down. This is the "Pony Express"
stage of interstellar communication. Invading fleets, escaping criminals, and similar
menaces might be able to outrun the warning that they're coming.

Of course, if instantaneous jump drives or stargates exist, then news and mail
delivery can be very fast indeed. Systems that aren't yet part of the stargate network
will still have long waits for mail and news.

Interplanetary trade is risky when a trader doesn't know in advance what the
market will be for his goods. A trader who guesses right can get rich; otherwise, he
can go broke. People seldom travel far on the cosmic scale, the galactic capital seems
remote, and citizens are more likely to be loyal to their provinces than to the nation.

If the nation needs a military fleet, it must be large in order to keep enough
strength everywhere it might be required. Consider the huge British navy of the 17th
century. Warfare will require careful planning, but captains (and frontier governors)
will have great leeway when they are months from new orders; bravado and strategic
skill will be very important.

Travel is always an adventure, because recent news of frontier areas is impossible to come by.

Slow FTL Radio -

At this stage, simple messages can be sent at speeds two or three times that of
the fastest starships. However, this is expensive. Routine messages must still be sent
by courier. FTL communications might be a government monopoly. FTL transmitters may be so large or costly that many worlds must still rely on couriers. Ships in
normal space can receive messages in mid-flight, but cannot send their own FTL
messages. This can be considered the "telegraph" stage of FTL communications.

Traders who can afford access to FTL communications will have a big advantage over their rivals, except in frontier areas without FTL stations.

Space navies can be smaller, because fleets can be centrally located and called in
time of need. This is also affected by the ships' own travel speed; most nations will
want to be able to muster significant force on notice of not more than a day or two.
But opponents will be able to muster large fleets more efficiently, too. Captains on
patrol will have great autonomy, since they can't depend on getting up-to-date
orders, but border worlds may be in close touch with headquarters.

Fast FTL Radio -

At this stage, communication between nearby star systems is cheap and many
times the speed of the fastest ship. Courier vessels are only necessary during the earliest stages of a planet's colonization, until an FTL com station can be built (even
then, ships' FTL radios can be used), or when communications are too sensitive to
be entrusted to the spacewaves at all. Ships and planets can communicate freely with
each other, except for ships in hyperspace.

Trade becomes much safer, with fewer risks and rewards, when a trader can
check the market at his destination before taking on cargo.

Fleets can be even smaller but still used efficiently, because warships can be
scattered throughout the nation on patrol, yet quickly called together in an emergency. Captains will rarely take action without checking HQ for orders. An analogy
would be the police cars of a 20th-century city.

However, even fast FTL radio has limitations. These are up to the GM to set.
The point, of course, is to produce situations in which a call for help is impossible!
Interesting possibilities include:

Limited range. Maximum range may be a few parsecs or thousands.
Alternatively, a radio's range might vary depending on its quality and the power
being used. The device may work only close to a gravity source – or only in deep
space. It may be necessary to build repeater "beacons" at regular intervals, either
ground or space based.

Static. Reception may decrease sharply, depending on the environment – stellar
density, radiation, gravity wells, and so on. If FTL radios are sensitive to gravity,
then each inhabited system may have to establish a communications relay in orbit
about a main world, or even beyond the solar system.

Delay. Even if messages travel far faster than ships, there will be a delay when
contacting someone far away. The GM should decide exactly how fast messages
travel. (Perhaps a more expensive "radio" sends messages faster.)

Energy drain. The GM is free to modify the energy cost of the units given in
Chapter 8. Conceivably, an FTL broadcast might require so much power than a ship
cannot use its engines and radio simultaneously.

FTL blocking. FTL communicators might not operate, or might be seriously
hampered, while the ship is in FTL travel. And hyperdrive ships, by definition, cannot contact the outside universe. If ships cannot communicate during FTL, that may
be a direct reason for some voyages – military missions, for instance – to drop out of
FTL and communicate with home base.

Unlimited FTL Radio

Swift, unlimited communications create a universe similar to 20th-century
America, where a great deal of information is available at the touch of a button –
perhaps including surveillance of enemy forces (equivalent to our satellites today).
Any vessel can be contacted at any time; the size of military fleets is governed only
by the size of the opposing force and the speed with which trouble spots can be
reached.

This is sometimes too much communication for an exciting campaign. Travel is
less of an adventure when news from all over the galaxy can quickly reach any civilized world. And worlds may become more and more alike – everywhere begins to
look like Galactic Prime (or California).

But it can still be exciting if the ships are comparatively very slow or the range
of a ship's own system isn't too great. Thus, an exploring craft may be out of communication for long periods. Worse, it may be within range of unhelpful advice from
the chair-warmers back at HQ.

"Survey Control, a mutant space amoeba just ate the stardrive! What do we do
now?"

"Survey 1138, it will take about a month to route a rescue craft to you.
Meanwhile, the scientific staff wants some information on that amoeba. Here's Dr.
Gzint."

"Gzint here, Survey 1138. What color is that amoeba? Please send somebody
out to take its temperature. Can you tell if it's carnivorous?"[/q]