Star Systems

Star Systems is a tool to help referees manage campaigns for the Traveller role-playing game or other science-fiction RPGs, such as Cepheus or Stars Without Number. The setting can be imported directly from the TravellerMap or created from scratch, or a combination of both.

The campaign management tools save time for the referee, and the ship creation tool can be used to create a new ship or recreate a ship from the rulebook for use with the app. The starships are compatible with the Mongoose Traveller 2nd edition rules, including all the High Guard options.

There is also a trading tool to facilitate market creation, the purchase and sale of cargo and the taking on of passengers. This tool integrates seamlessly with both starships and the campaign management tool, providing ship manifests and automatic notes.

Star Systems is a macOS application. Before downloading, please check the system requirements.

Star Map

The star map shows an area of space from a few star systems to whole sectors. In Star Systems this is referred to as the "Universe." You can have multiple universes, but only one can be active at a time. Universe management is done by the menu in the lower part of the left sidebar. You can create a new universe, rename it, delete it, back it up, or restore it. You switch between universes by opening this menu and slecting a universe and choosing the "switch to..." menu option.

Systems are located on the map by coordinates. This uses the same conventions as the Traveller Map: a sector is 32 hexes wide by 40 hexes tall. Subsectors are 8 x 10. Sectors coordinates are a bit different: negative numbers are represented by letters, starting with A for -1 and B for -2, etc. This way the coordinates A1-1024 are for the sector one left and one up from the central sector.

Note that this app has a different convention than the TravellerMap for sector coordinates: This refers to the sector's own coordinates, not the hexes within it. Traveller Map has a reversed Y-axis compared to Star Systems. In the TravellerMap the Y increases going down or Rimward, while in this app Y increases going up or Coreward. This isn't an issue when importing data from the TravellerMap since the app makes the conversion to its own coordinate system and people rarely use sectors' coordinates and refer to them by name instead, like 'Core' or 'Spinward Marches' when talking about them, and coordinates use a shorthand for sectors, like 'DENE 0339' that Star Systems reproduces exactly.

I chose to put the stars of a system in the middle of the hex instead of the traditional planet1. The star's color and the size of the circle represents the spectral and luminosity class respectively. I put the planet in the lower right corner which is typically unused. I also decided to put the amber or red zone indicator around this planet instead of the the traditional "whole-hex circle" version. This way let's me use the hex itself as a marker for the group's current location (see below). The rest are the standard gas giant and naval or scout bases presence, and on top the best starport in the system.

The name in the hex is the name of the star system, not the main planet as in Traveller, although in a Traveller universe both are the same: the Traveller Map importer gives the name of the main world to the star system. So in a custom setting you could have a star system named Sol and its mainworld named Earth.

System Card

When you click on a system, a card appears in the lower right part of the map. It shows a lot of information about the system and its planets. For TravellerMap imported data, the second survey details that don't have their own parameter in Star Systems' UWP (importance, economic, cultural, nobility, and resource units) are put into the world's comments. Allegiances automatically creates factions that appear in the faction list. Optionally you can create race factions, as the Amindii in the example below.

You can copy the system information to the clipboard by pressing the documents icon on the system card. Pressing the question mark button opens a window with a plain-English version of the UWP.

The 'timer' icon on the system card opens a tool that displays travel times. It shows both the times to the 100D safe distance for jumps for various thrust, and an interplanetary travel time between the system's bodies. It takes into account the star's shadow, i.e., if the 100D from the star is more distant than the 100D from the planet, which occurs for orbits close to the stars. It also takes into account binary systems, with travel times between planets from different stars in the system.

If a campaign is currently active, each time is a button that adds the listed time to the campaign's time, although there is a better way to achieve this in the Campaign view itself.

Faction Information

The card shows factions and world tags for the system. Clicking on a faction tag opens a Faction Information window. Factions support Stars Without Number's faction play, but can also be used for Traveller by just using the name and description. Importing from TravellerMap automatically creates such factions form the imported data. If you want to use SWN faction play with the data imported from the Traveller map (and you should), you need to add the additional information yourself.

UWP Reference

You can access a floating window that shows the meaning of all the UWP entries. This shows what each value means, including for the 2nd survey extensions.

Campaign

The campaign panel is the heart of Star Systems and it is linked with the universe, the Trade panel, and the Starships panel. It lets you keep track of multiple campaigns simultaneously. Each campaign has a 4-letter code which is used to switch between them.

Each campaign may be associated with a universe and a starship if the group has one2. This panel's focus is to help referees. It keeps track of where the player characters are, the date and time, and what happened in the past that took them where they are now.

Overview

The top section has the campaign name, a description, a ship selector, and the common credits the group share. This is used for transactions related to their ship, like paying expenses, and with for trade.

Below that are the main controls. The calendar with campaign's time and date on the left, and the current location in the middle. On the right is a help panel which list one way to use the controls, and at the bottom has a reminder of what you did last. Each of these sections are detailed below.

Next is the players' section with a list of player, their character's name, and the roles they generally play within the group. 'Players' can include NPCs.

Clicking on a player opens the information that Star Systems tracks about each player/NPC. This isn't a complete character sheet, since this is generally handled elsewhere (VTT, paper or PDF character sheets, etc.). What it does track are things that Star Systems needs or that the referee might want to keep track of at the same place as the time tracking for the campaign, like skill training, pensions, etc. A limited number of skills, stats, and ranks are also tracked because they affect trade. And there is a section for notes of course.

NPCs are created by checking the NPC box. This adds a salary field and sets the player's name to NPC. It is assumed that only NPCs are due regular salaries and the group members decide how to share profits or wages among themselves and with the NPCs.

The last section contains the campaign notes. These can be added directly by the referee or generated automatically by some actions like buying cargo or delivering passengers. Notes have a date, a title, and optionally a 'content' with more details. Optionally you can set a note to have a marker on the calendar. Notes that have a date corresponding to the current campaign date are highlighted (as the 5th note in the example above is). There are various options to sort, seach, and order the list of notes.

Campaign Selector

The top contains a number of controls and the campaign description. The description is for the referee, to remember the general context of the campaign when switching from one to another or when coming back to it.

You can have multiple campaigns in parallel. You switch between them by using the campaign selector. Each campaign has a 4-letter code used for this selector as well as internally for data storage. When you switch from one campaign to another, the current universe switches to the selected campaign universe. So if you were running the Cluster Truck campaign (TRUC) in the Estuary Cluster area and you switch to the Deneb Adventure (DENB), the universe switches to the Deneb sector for example.

On the top right are several controls. The first is the ship selector. It's set to 'None' if the group doesn't have access to a ship. The ship must first be created in the Starships section (detailed later). If you need to check the stats for the ship you can press the 'i' button next to it which opens a floating window with all the details of the ship. The starship selected here is used in many functions. The cargo capacity, the availability of high/med/low passage, thrust and jump rating, cargo crane, fuel scoop and fuel processors, etc. are all parameters that are taken into account for tools' logic.

Next is the amount of credits the group pools to handle common costs. Common Credits are used to pay ships costs like berthing fees or refuelling, and to pay salaries. Each player also has their own cash amount.

If you click on the 'Common Credits' label it opens a pool or distribute tool that lets you easily move credits to and from the player characters. This excludes NPC which are salaried.

The two action are 'Edit' to edit the campaign global parameters: the associated universe, the title, and the description. You can also export a backup file of a campaign so you can restore it later. I often backup a campaign in its 'start' state so I can run it again. This backup only saves the campaign data, not the state of the universe or the starships for example.

Campaign Date & Time

Date and time are represented in the standard Traveller way as HH:MM-DDD-YYYY. The standard day is 24 hours. The standard year is 365 days long. The first day of the year is special and is called Holiday. Starting on day 2, each week has 7 days. Each month has 4 weeks and also corresponds to a 'maintenance period' in this app. There are 13 months in a year. Holiday is considered part of the first month. The calendar shows a month at a time.

Time is usually only tracked to the nearest 10 minutes but some of the time management buttons may add a more precise time, like 53 minutes. If that happens and you'd rather only track to the nearest 10 minutes (like I do) you can just press the time & date title at the top of this section and it will round the minutes to the nearest multiple of 10.

You can set the current date simply by clicking on its number on the calendar. Notes that have 'show on calendar' checked add a highlight on that date (as shown for the 95th and 98th in the picture above).

There are various way to adjust the time, from the '+1M' (month) to the '+10m' (minutes). In addition there are some buttons that handle the length of some tasks. These only handle time management, there are no skill rolls associated. "Find a Broker" task are handled in the Trade panel.

• Take off / Land: if the ship is landed this will show 'Take off,' otherwise it will show 'Land.' This add 30 minutes to the campaign time for a starship with Thrust-1, 20 minutes for Thrust-2, and 10 minutes for other ships. It requires a ship selected and the app checks it for its Thrust rating.
• Astrogation: this will add the time to plot a jump: 1D x 10 minutes. See below.
• Broker: add time to find a broker: 1D x days. This is the same time range for both black market or regular brokers although they use different skills.
• Cargo: This is only enabled when a ship is selected and it has a cargo manifest. It adds time to load or unload the cargo. Since the time it takes to load cargo is not specified in the rules, I set it at 10 tons/hour with a cargo crane, or 5 tons/hour without. This checks the ship for a crane and check the actual cargo tons in the ship's manifest and adds the calculated time to the campaign clock.

Note that pressing any of these time management buttons puts a message on the help section on the right. This way to can remember what you last did and see what was rolled if there is a random element.

Campaign Location & Ship controls

The current location's coordinates and the travel status are shown in the title at the top.

Location is selectable from dropdown menus: system, planet, and satellite if the planet as any. Just below that is a travel status selector.

LND: On planet / landed
ORB: In orbit above the planet
STP: Docked at the starport
IST: In-system Transit. Moving through the system, generally to and from the 100D limit
HYP: In hyperspace. Selecting this or pressing 'Depart' changes the 'Current location' to 'Destination' which lets you pick your next star system.

Interplanetary Travel

To the left of the travel status selector is a button that opens an interplanetary travel computer. It lets you select any two bodies in a star system and gives you the time it takes to get from one to the other at various Thrust ratings. The time given are buttons which you can press to advance the campaign clock by the travel time.

Berthing Fees & UWP

If the travel status is either STP or LND and there is a starport that charges fees, the berthing fees button enables. Pressing it pays for a week of berthing fees. Prices depend on the starport quality as listed on page 257 of the core rules. As there is a random element to the berthing fees, the first time you press the button in a system a berthing roll will be made and saved in the system comment for later use. After this the cost will be displayed in the button itself and will be the same the next time you visit this system, as specified in the rules.

Next to that is the full UWP of the current location. The Star Systems UWP includes day/year periods durations, which can be useful to know during play. Clicking on the UWP opens a floating window with a plain-English version of the UWP and some additional information, like gravity.

If the ship needs refuelling, and refuelling is available at the current location, options will be available on the next line. In the example above, since the starport if a C quality, only unrefined fuel is available. Pressing the button will add the missing fuel to the ship at the standard cost and add the random time necessary to refuel. If refuelling with unrefined fuel and the ship has fuel processors, the 'Process Fuel' will be available. This will check the processor capacity (in tons per day) and add the required time to the campaign clock, converting the fuel to refined fuel in the ship's manifest.

Maintenance & Life Support

As time passes, monthly maintenance and life support costs should be paid. The app never pays these for you but it helps you keep track of them by showing a 'due badge' when they should be paid. If you miss two months maintenance, a 'x2' will be shown. Pressing the buttons will remove the amounts for the full dues from the common credits pool. These costs come directly from the ship's details.

Jump Controls

The bottom of this section is used for jumps. The first button shows the time between the location (planet) and the jump-safe distance of 100D. This takes the star's 'shadow' into account if the planet is close to the star. Pressing this simply adds the time to the campaign clock. It doesn't change the travel status because it's used in both direction, coming from the 100D and going to the 100D. Next to that is the jump distance for the next jump you're planning. The maximum jump depends on the ship selected. This is used to handle fuel, shown as a comment further right. The 'Depart' button logs the departure in the campaign notes, switches the travel status to hyperspace, and burns the selected jump distance's fuel. It also changes 'current location' to 'destination.'

Normally, after pressing depart you'd roll 6D for the jump time variance. You can enter what the roll is or press the 'Roll' button to have it rolled by the app. You can then press the Add Jump Time to add this time to the clock. If 'Log note' is selected, a campaign note will be automatically added for the jump.

All this procedure is details right next to these controls for easy reference.

Jump Procedure and Last Action

The last panel in this section is a cheat sheet of the jump procedure. Below that is a line stating the last action taken, showing variables when there are any. Of course it's not necessary to do all of that—you can just change the location to another system— but following it leaves a nice crumb trail in the notes and helps accurately keep track of time and fuel status. It also meshes well with the trade tools we'll see below.

Players' information

The players' information section gives the referee an overview of the players' characters names and roles. At the top are buttons to add a player, reset all markers, or add one week of training to every player that is currently training a skill.

Markers are incremented each month and help track pensions and other monthly credit transactions. One of these are the salaries due to NPC. On the top left is a button that enables when salaries are due, and pressing it will pay all due salaries at once from the common credit pool.

You can of course advance training or pay salaries individually for each player.

There are player characters and NPC and both share the same parameters except for salary, which only NPC get.

Selecting a player reveals more details and lets you edit all the information for that player.

Campaign notes

Notes can contain only a title, or a title and additional content which you can disclose by clicking on the note's title. Notes have date and time associated with them (defaults to the current date and time), and can optionally be highlighted on the calendar.

Notes titles for the current date are highlighted in the notes' list as shown for the thrid note above.

Notes title and their content is searchable. You can also add an end of session note that automatically by clicking a button. You can then add details about the situation the characters are in as the session ends.

Trade

The Trade panel is used to generate a market, evaluate options, take on passengers and cargo on a ship and, when at another world, deliver passengers and sell cargo. Everything is done according to the Mongoose Traveller 2e rules (pages 238-245).

The default world and starship selected are as those currently set in the Campaign panel. This tool shows the common credits available for trade and the capacity of the ship, both in cargo space and in passage it can offer (High/Middle/Low). This information comes directly from the ship.

You can decide the maximum range to consider to generate the market. The app will look at all the systems within that range from the current location to evaluate passengers, mail, and cargo.

You can also set the opposing broker/supplier's Broker skill and choose which type of market to generate:

• passengers
• Freight
• Mail
• Speculative Cargo
• Black Market Cargo

You then set who the negotiator and steward are. These can be selected from the players (or player-npc) or left open and you then enter the skills/ranks in the fields. These stats are used in the player rolls section below.

Next you enter what the players rolled for the various markets, or you leave a field blank and the app will roll randomly. Each type shows the applicate DMs for the current world/negotiator/steward.

On the other side of the divider you'll see the world's trade codes and the DMs, and each type of market also lists applicable (if left to roll automatically) or applied if you entered a roll.

Once everything is set you press the 'Genera Market' button at the top right of the window to process everything and generate a market and evaluate prospects.

Once generate there are five sections below that: Ship's Manifest, Passengers, Freight & Mail, Speculative Cargo, and Checks. The first is what's currently in the ship. Since it will start empty we'll come back to it later.

Opening the Passengers section lists available passengers numbers (pax) for each location and passage type, and the passage cost. Pressing 'Book' accepts maximum number of passengers of that type that the ship can carry, leaving the rest available for the rest of the month.

Once booked, these passengers are transferred to the ship's manifest. If there are passengers to different destination, those appear under their own destination tab. The 'Book' buttons are then disabled since there are no space available for more passengers.

The Freight & Mail section has a menu at the top to accept mail for a specific destination. There is an 'Unspecified Destination' available in case the referee wants to keep the narrative open.

As you accept passengers and take on cargo, keep an eye on the remaining capacity at the top of the manifest. Freight is listed by destination. If there is no focus selected (see below) then the offers are sorted by distance. If you open a location there is a list of offers in this order: Major, Minor, and Incidental. Each has a number of tons, a price and an accept button. Those are all or nothing and those that exceed the ship current capacity are disabled.

Opening the speculative cargo shows all offers, including black market offer if that was selected (shown with a red warning sign). They are sorted by potential profit when no focus is selected (see below). These assessments are made with the average roll for both buying and selling, and by destination, where the trade codes are evaluated and the DM included in the evaluation.

Opening an offer show each potential destination within max range and the average (roll of 11), best (roll of 18), and worst (roll of 2) outcome considering that location's trade codes. In front of those are the profit margin for the average outcome and the profit/loss per ton. Green means a profit of 10% or more, yellow means between 0 and 10%, and red means a probable loss for that destination.

Pressin 'Buy...' opens a dialog where you can enter the roll the player made (or let the app roll) and the tons you want, pressing 'Buy' there add the cargo to the ship and pays for it.

Note that the app doesn't enforce the group to have the available funds in Common Credits. That is left to the referee and them to manage, in case they have a line of credit for example.

Once all your shopping is done, this is what your ship's manifest could look like.

Focus

If you know your destination you can select if in the 'Prospect Focus' menu (shown top right in the picture above). This will first add an indicator for availability on the passengers and freight section if there are any for that destination.

It will also sort the speculative cargo section by highest potential profit at that destination instead of highest overall profit.

Selling

When you arrive at your destination the ship's manifest will flag any content for that particular location.

You can then sell or deliver freight, passengers, and mail.

You can then sell your speculative cargo, which is similar to buying. You enter the player's roll and press sell. You need to have generated a market for this location with the same procedure as above. The whole process is summarized in the upper right of this panel.

Starships

Above is what the PDF exported from Star Systems looks like for the example in this section.

Ship Design

You can open a ship design window with command-shift-s, or select the 'Starships' panel from the sidebar and press the 'new' button.

The design window is in two parts. The left side shows all the design steps in order, with the options for each step grouped together, and the right part is a summary view, similar to what is shown in official published starships. As you fill in details this summary is updated, and feedback is given in the interface to warn you about issues like missing power for example.

The options cover both the core rules and the High Guard rules, although it is not designed (or tested) for ships larger than ~2,000 tons.

Once you have a design that you like and want to save, you can give it a configuration name, a type, a name, and a description.

And then you can add one or more images. They show a thumbnail in the interface and when you click on them they open in a floating window that you can resize (and show to your players).

You can also create variants by loading a starship, making modifications and saving it as a new ship.

In addition to what is generally shown in the published ship summaries, there are sections for running cost, including maintenance and life support costs. These are used in the Campaign panel and are part of the monthly tracker.

And if the available power isn't sufficient to cover all the systems, a 'normal operation' and a 'jump configuration' section are added. And if the available power seems insufficient to run in a viable configuration it will give a warning.

Route Planner

The Route Planner finds and displays the best route between two systems for a ship of a chosen jump-drive rating, thrust, and scooping capability.

Best route is based on the fewest number of jumps, then on the shortest total distance. Each jump is evaluated at 148 + 6D6 hours (≈ one week). In-system maneuvering flies from the main world to the 100-diameter jump point when leaving a system and back to the main world or a gas giant in the system for refuelling. All maneuvering are computed at the given thrust. Refuelling at starports A/B is with refined fuel and at C/D with unrefined. If the ship has fuel scoops, systems with either a gas-giant or water can be included in the route. Skimming includes the round trip out to the giant and back or water scooping at the main world.

You have the option of creating a series of Routes with a given faction to represent the planned route on the Star Map. Alternatively you can also open the details in a floating window and switch to the Star Map to review the plan.

When importing from TravellerMap, some systems don't have starports or fuel scooping options, but still provide fuel. For example Chandler Station and Riftspan Station have refuelling capabilities but not water, gas giants, or starports. In cases like these, add a Refuelling-Stop world tag to these system and the Planner will allow a route to pass through.

Systems

The 'Systems' tab displays a searchable list of all the systems. You can display only a specific subsector, and you can sort by either coordinates, system names, or main world names. If you click on a system you get a more detailed view with all the bodies in the system with their UWP. It shows planets, gas giants, and satellites. Those with population show an icon and the population.

From there you can go into edit mode and modify any of the bodies in the system. You can edit all parameters, for example changing the atmosphere of a planet. You can add system notes, world notes, add names for bodies, and add factions and world tags to any of the bodies in the system.

Information

A global information panel offers statistics for the current universe. The information is provided for the whole universe, by sector, and by subsector. It lists a number of data as shown in the picture above.

Routes

Once you have two systems or more you can add "rutters" which are routes between star system. In Stars Without Number these have game mechanics attached which are supported: they are associated with a faction and have an 'age' parameter. In a Traveller map they are called routes. You can enter the end point by coordinates or simply select star systems by name.

Nebulae

You can also add five types (i.e., colors) of nebulae simply by adding a list of hexes. Nebulae aren't used in Traveller but they can enhance a map, or you can have them have mechanical effects, like disrupting jumps, in your games.

Regions

Regions are defined by a list of hexes and vertices points. The app computes the shortest path between these and traces the region, which can be open or closed. Each region has a label that is automatically placed in the computed center of the region or on a specified hex. For example this is the Sundown Reaches region in the Star Frontiers map which is defined by 6 hexes and has a custom-placed label.

You can choose to have a background for a region.

Labels

Finally you can also add labels anywhere on the map, specifying a hex location, the font size, the color, and a rotation angle. In the context of Traveller I use them for sector and subsector names.

Generator

Whether creating a setting from scratch or customizing a sector imported from TravellerMap, you may want to generate complete star systems or simply fill out additional bodies to the single body per system that TravellerMap provides.

This star system generation follows the Traveller5 (T5) world generation rules referenced in Book 3. This is also what is used on the Traveller Map, so everything is compatible with it and with Mongoose Traveller 2nd edition. The only difference for Stars Without Number are the tech levels.

You can use either the Stars Without Number (TL0-TL6) or the Traveller (TL0-TL22) Tech Levels. Once you've created a star system with on of these TL systems the universe is locked into this mode.

You can specify the star's spectral type, temperature, and luminosity class or these can be randomly generated. You can specify the tech level of the system or generate it randomly with a cap. All the bodies in the system are generated with full Universal World Profile (UWP), including all satellites. Day and year length are computed for all bodies as well.

You can change any of the bodies and their UWP, or make a system from scratch if you want to reproduce a given system in a source book. For example say you want to reproduce this star system.

You can easily recreate is in Star Systems. You can give names to the stars, any of the bodies, and set every parameter.

Traveller Map

You can import a whole sector by name, e.g. "Spinward Marches", or one of its subsector, and you can choose which milieu, or timeline, you want to import. For example this is an import of the Spinward Marches sector.

You can import multiple sectors if you want.

After you import the Trojan Reach sector from the TravellerMap for example, you can customize its settings to suit your preferences.

And add the regions defined in The Borderland setting book.

Additional Worlds

The Traveller Map only contains information about the main world of a system. It states the number of bodies, the number of gas giants, and the number of asteroid belts, but it offers no other information that this through the API.

The default when importing from the Traveller Map is to only import the main world information, but you have the option to procedurally generate the additional bodies in all systems on import.

Alternatively, you may choose not to generate those worlds on import, but instead generate them as needed for individual systems. For this you go into the edit world panel and press the button in the toolbar.

SEC Files

The app supports importing both legacy and T5 formatted SEC files. It auto-detect which format the file is in.

You can also export a SEC file from the currently selected universe. This is always in the current T5 format. This exported file contains additional information, not supported by the TravellerMap import, but is still compatible with it. The additional information is put in comments which the TravellerMap parser ignores. This additional information is parsed when imported into Star Systems, so two people can exchange universe information while preserving regions, which are not supported by the standard SEC format.

System Requirement & Support

Star Systems is a macOS application. It requires macOS version 26.5 (Tahoe) or higher.

To ask questions, report bugs, ask for features, or just share how you use the app, please join us on Discord.

Copyright Notice

This application, including all original code, interface design, and non-licensed content, is © 2024-2026 Denis Ricard. All rights reserved. This application is all original code and is not derived from any other source.

The TravellerMap importer uses public API. The Traveller game in all forms is owned by Mongoose Publishing. Copyright 1977 – 2026 Mongoose Publishing. Traveller is a registered trademark of Mongoose Publishing. Mongoose Publishing permits web sites and fanzines for this game, provided it contains this notice, that Mongoose Publishing is notified, and subject to a withdrawal of permission on 90 days notice. The contents imported from the TravellerMap are for personal, non-commercial use only. Any use of Mongoose Publishing’s copyrighted material or trademarks and its files should not be viewed as a challenge to those copyrights or trademarks.

This program cannot be republished or distributed without the consent of the author.

Disclaimer of Warranties and Limitation of Liability

This software is provided “as is,” without any express or implied warranties of any kind, including but not limited to warranties of merchantability, fitness for a particular purpose, or non-infringement. The developer makes no guarantees regarding the functionality, reliability, or suitability of this software for any purpose.

In no event shall the developer be liable for any direct, indirect, incidental, special, exemplary, or consequential damages (including but not limited to loss of data, business interruption, or financial losses) arising from the use or inability to use this software, even if advised of the possibility of such damages.

By using this software, you agree that you do so at your own risk. You are solely responsible for any damage to your device, data loss, or any other issues that may arise. The developer assumes no responsibility for maintaining, updating, or providing support for this software.

By using this software you agree to these terms.

Additional Resources

• There is a video showing some of the features of Star Systems.
• And a video on the Route Planner tool showing how it works.
• You can find more resources for Mongoose Traveller on this MgT page.
• You can find more resources for Traveller5 on this T5 page.
• Other resources for role-playing games.

Release Notes

version 1.0.175 — Initial Release

versions 1.0.185

• some adjustments to dark mode colors
• refactored the way multiple routes between the same end points are drawn
• make world name all caps if population >= billion in card and copied text on system cards
• refactor to add categories to labels so they can be turned on/off
• shown labels are saved per universe. TravellerMap now add ‘Subsector Name’ and ‘Sector Name’ categories automatically
• add the option to generate missing worlds when importing TravellerMap data
• also enable per-system additional worlds generation

version 1.0.190

• change background color of sector picker
• change text color for world tags in dark mode
• shorten labels for day and year length in the plain-text window
• change the binary star orbit determination when importing from the TravellerMap. TravellerMap doesn't provide orbit information, now use the system generator’s companion orbit logic which puts the companion is a much higher orbit
• now all imported routes from the TravellerMap are set to major trade routes so they’re visible in the players view. I also fixed the short names for Trade Routes from 'RT' to 'TR'

version 1.0.195

• change the way world notes are edited to allow for larger notes
• fix sidebar's lower section transparency
• lower requirement to macOS 26.5

version 1.0.200

• add main world name and UWP to players' system card
• star map display options are now preserved when switching views and on relaunch
• add a 'Travel Times' button in the system card to display both interplanetary travel time and travel time to 100D limit for jump. This includes the star's shadow (when the star's own 100D is greater than the planet's 100D) and supports binary systems (travel times between planets orbiting different stars)
• fix display of trinary system in star map and in system card

version 1.0.205

• add a 'Star Reference' information window
• fix a possible bug where the sound when selecting a system stopped playing
• improve display of system card to accommodate both longer world notes and system bodies

version 1.0.210

• fix a bug in the sector coordinates stepper preventing the proper range in some cases
• added the option to show/hide routes distances on the star map (persisted)
• increase size of various text editor font
• remove duplicate world notes display in system details

version 1.0.215

• change disclosed padding of factions list under categories
• use faction category icon in faction list

version 1.0.220

• for Traveller settings, do not display the main world's name since the system's name is the same
• fix description of dwarf stars

version 1.0.225

• add route planner tool. It finds the shortest route between two systems based on jump, thrust, and fuel scoop capabilities3
• add a specific symbol for system tagged {Anomaly} instead of a planet or asteroid

version 1.0.231

• star map zoom level and center position are now preserved between switching views or launches (you can still double-click to zoom out to full view)
• fix some alignment in the route planner floating window header
• add a Trade Code filter on the star map (systems not containing all trade codes selected are dimmed but still selectable)
• play error sound when no system with selected trade codes are found [231]
• fix spelling error for refuelling-stop world tag [231]

version 1.0.235

• add Discord link to about window
• make version info in sidebar a button to open about window
• add the number of systems matching the currently filtered trade codes
• completed implementation of faction parameters compatible with Stars Without Number (completely optional for Traveller)
• use Traveller conventions for coordinates labels in some places, e.g., Troj 2819 instead of D0-2819

version 1.1.240

• add campaign management
• add import/export of SEC files for custom universes (supports both legacy and T5 format for import, auto detected, export to T5 format). The import is untested, feedback welcome.

version 1.1.245

• fix a bug where campaign notes would not be editable in some circumstances
• add a role parameter for player's information in campaigns

version 1.2.260

• greatly improved campaign data and management, with integration with new trade tools, many tools to help with time and current location tracking
• add starship design/validation tool (open with command-shift-s) with option to save starships
• add Trading tool (generates cargo and evaluates markets within range, etc)
• implement full system edit to enable matching of published systems (named stars, named gas giants, set planets/gas giants/planetoids belt to any orbit, add any satellite to any body, etc.)
• add more data in 'Information' panel, including trade codes, factions and races data, as well as per subsector data
• now you can optionally add custom races automatically when importing from TravellerMap. You can also manually add custom races
• make SEC file import more robust to format
• add command-f to focus on search field in star map view
• add export to PDF for starships
• fix a world generation bug that sometimes gave bigworlds an undefined
• improve starmap drag and pan responsiveness for larger universes

version 1.2.265

• add export/import for starships. Export creates a folder with the data (json), a folder with all the images, and a PDF of the starship
• improve format of Edit/Save Details for starships
• improve support for carried crafts in starships
• fix issue with starship PDF export that could happen and leave some text not being properly exported
• make faction section collapsable in the sidebar
• sort routes, regions, and labels lists properly
• make sell/deliver buttons closer to the manifest content

Latest release notes

version 1.3.270

• add 'check for update'! No longer required to download a new version each time.