My #TravellerRPG #Wargame – Using @IndependenceGa6 The Clement Sector setting in High Guard

Ever heard of Eurisko? If you played the (now Classic) Traveller RPG back in the early 1980’s, and especially if you played with capital ships or fleets in Book 5: High Guard or Adventure 5: Trillion Credit Squadron, then you probably heard of it. Eurisko is a representational language written in the Lisp Programming Language that learns through heuristics. Think of it as an early form of AI. Eurisko was used to design the 1981 winner of the Traveller Trillion Credit Squadron National Tournament at the Origins Game Fair that year. In 1982 Eurisko won again. Threatened with the end of the tournament if he entered again, Dr. Lenet withdrew Eurisko from further competition.

I bring up this history because the Eurisko incident often colors many peoples perceptions of High Guard. Since High Guard could be ‘gamed’ by a computer, many decry it as ‘broken’ and not a worthy version of a fleet battle game for the Traveller universe. I disagree. I enjoy High Guard and the companion Adventure 5: Trillion Credit Squadron. Sure, it’s a highly abstracted view of space combat in the Traveller universe, but that very abstraction is what makes it attractive.

The Traveller Itch

Having not picked up a Traveller book in a while, I recently had an itch to dive back into the rules. One awesome aspect of the Traveller series that I really enjoy is all the mini-games possible. From Character Generation (yes, I’ve died in CharGen), to world-building, to building ships, the rules of Traveller, and now the modern successor Cepheus Engine, allow you to create a wide diversity of elements in a system that ensures it all works together.

The Clement Sector: Core Setting Book from Independence Games

One setting for Traveller I really enjoy is The Clement Sector from Independence Games. The Clement Sector is a ‘small ship universe’ where the limits of the “Zimm Drive” keep ships, at least those that are jump capable, under 5,000 Tons. With the Wendy’s Guide series of sourcebooks that detail out entire fleets, I wondered if The Clement Sector and High Guard could mix. So I experimented.

Anderson & Felix, Meet High Guard

Ships in The Clement Sector are constructed using the Anderson & Felix Guide to Naval Architecture. If you are a Traveller RPG historian, you will know that A&F is basically the modern day version of Book 2: Starships updated for Cepheus Engine. This means that A&F is not closely coupled to High Guard like the original Book 2: Starships or Adventure 5: Trillion Credit Squadron were. For my experiment this meant that in some places a little “interpretation” is needed to convert ships from the A&F stats to High Guard which uses the original Universal Ship Profile (USP). The USP was a series of numbers that takes much the details of a ship design and renders it into a single line alpha-numeric characters.

Powerplants, Energy Points, and Agility

In the original High Guard, ships were built with Powerplants that in turn produced Energy Points. As Book 5 stated, “Energy points are used for four purposes: powering weapons, shields, for maneuver drives (for agility), and for computers.” The key factor for High Guard was that ‘Agility’ rating derived by taking energy points not used for computers or weapons or shields and plugging them into the formula A=E/0.01M (where E= Unused Energy Points and M= Mass of the Ship).

Agility is one of the most abstracted elements of the High Guard design in a design that is full of abstractions. Book 5 defines it as follows:

Agility is the ability of a ship to make violent maneuvers and take evasive action while engaging hostile targets. A ship’s agility rating may never exceed its maneuver drive rating.

Book 5: High Guard (2nd Edition 1980), p. 28

It’s clear that Agility is distinctly different that a ship’s maneuver rating. Seeing how it is based on “excess power” it (at least to me) symbolizes how much more you can throw your ship around beyond the usual M-Drive abilities.

Which is the heart of the problem. You see, in A&F the energy requirements in a ship design are actually more simplified than in High Guard. The concept of Energy Points is simply not used in A&F. Unlike High Guard, in A&F computers and turret weapons (presumably this includes barbettes too) are “Unlimited by Power” per the Capital Ship Armament Table on A&F p. 29. This same table specifies how many Bay Weapons per 1000 tons can be carried (based on the Power Plant Rating) as well as if a Spinal Weapon or how many Screens are allowed.

Without a direct translation between High Guard Energy Points and the Armament Power Table in A&F it is impossible to derive an Agility rating. So I asked myself, “How is Agility used in combat, and what would the difference be if it was not used?”

When resolving combat in High Guard, one nice part of the design is that there are actually very few modifiers to worry about (or remember). When making the initial To Hit roll, there really are only three modifiers:

  • + relative computer size
  • – target agility rating
  • + target size modifier

I was worried that, with this few modifiers to start with, simply removing the “- target agility rating” risked skewing the result. Wanting to preserve the intent of the design, I fell back on a lazy solution; change the modifier to “Minus Firers M-Drive Rating/Target M-Drive Rating (rounded down) IF RESULT IS POSITIVE – any NEGATIVE result becomes Target Agility= 0”.

For instance, say a Rattlesnake Attack Craft with M-Drive=5 from Ships of The Clement Sector 7 has jumped a Rucker-class Merchant from Ships of the Clement Sector 16 converted into the System Security/Escort Armament variant with M-Drive=2. When the Rattlesnake attacks the relative drive rating (5:2) computes to a factor of 2, giving the Rattlesnake a -2 DM on its To Hit rolls (better relative “agility”). On the other hand, when the Rucker shoots at the Rattlesnake the relative rating is 2:5 giving a result of -2 which becomes 0 DM modifier.


The second area that needed interpretation was armor. In Cepheus Engine ship combat, the armor rating directly reduces the number of hits. So when a ship is attacked with a salvo of three Basic Missiles (Damage = 1d6 each) launched by a Triple Turret, if the target ship has Armor = 8 then the first eight hits are offset. When designing a ship using A&F, the default armor for higher Tech Levels is Crystaliron which can be added to ships in increments of 5% of the ships tonnage. The maximum armor factor is the Tech Level of the design or 12, whichever is less.

In High Guard, the type of armor is unspecified. Given the rather large armor factors in A&F designs, I wondered it I was over-armoring the designs. A close look at the High Guard Hull Armor formula gave me my solution. The Hull Armor formula tells the designer the percentage of the ship required for that armor factor. At TL 11 (standard in The Clement Sector) the formula is 3+3a where a is the desired armor factor. Using a little backwards math I quickly discovered that the Armor Factor given in a A&F design was using too much space, but if I used the number of “layers”– those 5% elements- the number worked. So a Moltke-class cruiser (Ships of the Clement Sector 3) which is listed as “Crystaliron x2 / 8 points” when converted to High Guard has Armor=2. Unlike Cepheus Engine where armor directly reduces the number of hits, in High Guard armor is a +DM when rolling on the Ship Damage tables. Using this backwards derived formula, armor in The Clement Sector ranges from +1 to +4; a much more reasonable range of modifiers than the +4 to +16(!) using the A&F factors.


Torpedoes are described in A&F as, “…true ship killers…heavy 2.5dT anti-ship missiles….” In A&F missiles inflict damage from 1d6 (Basic Missile) to 3d6 + Crew Hit (Nuclear Missiles). Comparatively, a Basic Torpedo will inflict 4d6 hits, a Nuclear Torpedo causes 6d6 hits, and the heaviest Bomb Pumped Torpedo scores 7d6 damage.

Assuming the High Guard missiles are nuclear, I was able to come up with approximated damage for each USP factor. I then reworked the table using the higher damage potential of the Torpedo. In the end it worked out that I could use the existing High Guard Turret Weapons table and, using the missile column, simply add +1 USP factor to get the Torpedo USP.

Rail Guns

Rail Guns were another weapon found in A&F but not in High Guard. Using the same approach as I did for Torpedoes, I basically figured out that the 50-ton Rail Gun Bay had nearly the same hitting power of a 50-ton Missile Bay, so I used the same USP factor. The primary difference is in combat; the Short range of the Rail Gun earned it a restriction of being unable to fire when at Long Range in High Guard. At Short Range, the Rail Gun earned a +2 DM To Hit but used the Attacking Meson Gun vs Configuration table. This generally means that, absent those other To Hit modifiers, a Rail Gun battery needs to roll an 8+ on 2d6 to hit a Needle/Wedge configuration, or a 6+ to hit a Standard configuration, or an 11+ to hit a Dispersed configuration ship. Sort makes sense, right?

Missile Stocks

In High Guard the number of missiles one had aboard a ship was not a consideration. I always found this interesting given that combat in High Guard usually depicted larger, longer fleet engagements. The ship descriptions in the Ships of the Clement Sector includes the number of missiles on hand. Usually it is a mix of Basic, Nuclear, and Smart Missiles. As any logistics planner will tell you, you can’t face the enemy with an empty quiver of bows! I toyed around with the idea of breaking the load out into the number of turns each missile type could be fired (assuming one round of firing in a turn) but ultimately decided that breaking it out by missile is just too granular for the High Guard system of abstractions. Instead I took the number of missiles available and divided it by how many can be fired in one ‘volley’. This is the number of ‘volleys’ the ship gets before the stores are depleted. Probably only useful in a campaign game or as a special rule like an SDB on patrol too long facing a pirate with a near-depleted stores of missile– make every shot count!

Into Battle?

So, now that I’ve done my homework, will I actually play a game of High Guard in The Clement Sector? Maybe. Like I said before, The Clement Sector is a ‘small ship universe’ meaning space battles are usually smaller affairs with few ships. High Guard is better at resolving larger fleet battles with larger combatants. In the The Hub Federation Ground Forces sourcebook, Appendix 1, some details of the “Battle of Beol” are provided. There may be enough there to make a fleet battle scenario.

Now that I think of it, the Battle of Beol also includes a ground campaign. Maybe I need to look at a Striker (GDW, 1980) campaign next?


Feature image courtesy

#Coronapocalypse #RPG – A different #TravellerRPG future with @IndependenceGa6 #TheClementSector Earth sourcebooks

IN THE PAST FEW WEEKS, I PLAYED SEVERAL Traveller RPG-related wargames. Invasion: Earth (GDW, 1982) and Squadron Strike: Traveller (Ad Astra Games, 2018) are based on the Third Imperium setting. However, my modern “preferred” setting for my Traveller RPG is The Clement Sector from Independence Games (formerly Gypsy Knights Games) using their modified version of the Cepheus Engine ruleset.

A major reason I like The Clement Sector is that it is in the future, but not so far in the future (like the 56th Century of the Third Imperium) that I cannot relate. Here is how Independence Games describes the core setting:

In 2210, scientists discovered a wormhole allowing travel to the opposite side of the Milky Way galaxy.  Once across, exploration teams discovered worlds far more suited to human habitation than those in star systems nearer to Earth.  Were they terraformed by some unknown race?  Are they just a coincidence in the vast diversity of the universe?

Over the ensuing years humans left Earth and began to colonize these worlds.  Nation-backed colonies.  Corporate colonies.  People who simply no longer felt compelled to remain on Earth.  The best and brightest.

In 2331, the unthinkable happened.  The wormhole collapsed leaving those in Clement Sector cut off from Earth.  Now these new worlds and new civilizations must stand on their own.

The year is 2342.  Adventure awaits!

Originally, The Clement Sector focused in ‘the other side’ of the wormhole and the regions that grew up around there. I really like the setting because it has everything one may prefer; a subsector that is very Space Opera, another that is Space Western. I also absolutely enjoy how Independence Games makes their sourcebooks; a combination of wide topics with ‘seeds’ of adventure thrown in. They paint the broad strokes of the setting but leave plenty of space for you, the GM or players, to fill in. In an era when so many folks play IP-derived settings then complain of being ‘constrained’ by canon, The Clement Sector is a refreshing dose of freedom. Which is why I approached a few of the most recent releases with a bit of trepidation.

Earth Sector: A Clement Sector Setting

Earth_Sector_Cover_540xI actually talked about this sourcebook back in February 2020 and was not so keen on it then. Truth be told it has grown on me in the short time since. Earth Sector: A Clement Sector Setting focuses on the Earth Sector but AFTER the Conduit Collapse. I was concerned about this ‘alternate-future’ look and although there is certainly a good deal of ‘history’ in the product I am very pleased on the post-Collapse focus. Indeed, that is what saves the entire product for me – it is as much more of a look forward into the ‘future’ than a tie to the ‘past.’

A major reason Earth Sector has grown on me is another one of those Traveller games-within-games. As the ad copy for Earth Sector states:

Using the relationship matrix developed in Balancing Act: Interstellar Relations in Clement Sector, Earth Sector contains detailed reports on which nation is doing well, how much they are raking in from their colonies, and upon which nation they may yet declare war.

CTadv5Long ago, Classic Traveller Adventure 5: Trillion Credit Squadron included rules for determining budgets for a world. The idea was players could design and build fleets and fight with them. Over the years, this world budget concept has often cropped up in the game. Independence Games added their take on the concept with Balancing Act: Interstellar Relations in the Clement Sector:

It also includes a game within a game called “The Balancing Act”. This game will allow you to take on the role of a head of state in Clement Sector and go up against other leaders as you attempt to push your world ahead of your competition. These rules can easily be used in other settings and games where one might wish to become a leader of a world.

What I really like about Balancing Act is that it is not solely focused on the military (although that certainly makes up a large part of the ‘balance’). Although most RPGs are inherently very personal and focused on a individuals in a small group, as a GM I can use Balancing Act to ‘world-build’ the setting.

Subsector Sourcebook: Earth

EarthSectorFrontPromoCover_1024x1024@2xComplementing Earth Sector is Subsector Sourcebook: Earth. This product looks beyond the Earth and to the whole subsector. Again, the post-Collapse focus is what makes this product; there is enough history to broadly explain how the various locales came to be and how they are dealing with the post-Collapse situation. In addition to all the ‘details’ about the planets, this subsector book also includes the Balancing Act data meaning it is ready-set for GMs and players to start their own world-building adventure game.

Which brings me to the last new product this week…

Tim’s Guide to the Ground Forces of the Hub Subsector

Tims_Hub_Cover_Final_1024x1024@2x.pngIndependence Games already publishes their Wendy’s Guides for space navies in The Clement Sector. Tim’s Guide to the Ground Forces of the Hub Sector takes that same concept an applies it to non-space forces (ground, aerospace, naval) and organizations. Unlike the other products I talked about above, this first Tim’s Guide goes back to ‘other side’ of The Clement Sector and focuses on the Hub Subsector.

Like the Wendy’s Guides before, each planet has their non-space forces laid out. Planetary factors related to The Balancing Act are also included. As I so often say about Independence Games’ products, the depth of detail is just right. For example, one entry may tell you that the planet has a Tank Company equipped with FA-40 tanks, but they don’t tell you the details on that tank. It might be in one of the vehicle guides or, better yet, you can use the Cepheus Engine Vehicle Design System to build your own. [I guess it is just a matter of time until Independence Games publishes their own The Clement Sector-tailored vehicle design system too.]

The other part of this book that I appreciate is the fully detailed “Hub Federation’s Yorck-class Battlecruiser, a seafaring vessel capable of engaging forces both on the oceans and in close orbit.” The Traveller grognard in me wants to take this ship and place in a Harpoon 4 (Admiralty Trilogy Games) naval miniatures wargame scenario and see how it goes.

So there you have it; three new The Clement Sector books for YOUR game. That’s probably the most under appreciated part of Independence Games. Unlike so many other settings, The Clement Sector empowers the players and GM. There is lots of material to chose from, and many adventures to be created.

Traveller Tuesday – Clement Sector ATU

DrivethruRPG had a science fiction sale during the month of May and I splurged on several items. After watching from afar for awhile I invested in a series of books from Gypsy Knights Games (GKG). The Clement Sector is GKG’s alternate Traveller Universe (ATU) setting that uses the Mongoose Traveller (MgT) RPG rules.

The Clement Sector: A Setting for Traveller is the foundational setting book. The pdf version is 140 pages and provides a broad background of the setting including the history, politics, and religion. Sector and subsection maps with Universal World Profiles (UWP) for the entire sector is provided. Chargen uses the Traveller Main Book (TMB) with setting-specific expansions and changes. The major change is in technology with the “Zimm Drive” which effectively limits starships to under 2000 dTons solidly making The Clement Sector a small-ship setting. Five sample starships are provided, along with setting-tailored rule changes or modifications. Overall, The Clement Sector is directed to the referee and provides most of the necessary support to start adventuring in the Clement ATU.

Career Companion is a sourcebook (61 page pdf) focused on chargen and includes rules for uplifts and altrants (genetically modified humans). Most importantly are the ATU changes to the aging rules; in The Clement Sector the average human lifespan is 254 years. The other major chargen change from the base Traveller rules is SOC versus Wealth. Your SOC characteristic represents not your social status but your “apparent” wealth. This makes the characteristic fluid as one can change their SOC simply by spending more – or less – money each month on appearance, clothing, or lifestyle. Career Companion also includes new career tracks tailored for The Clement Sector as well as an advancement system. Career Companion is equally useful to the referee or players.

The Clement Sector Player’s Guide (115 page pdf) is in many ways an expanded Career Companion. It expands chargen by adding more background (languages, events for youth/teenage/collegiate life) as well as more career options. It also introduces Character Packages, a collection of directed career builders. New skills are also introduced. Like the title says, this item is aimed at the Players though referees will find it useful too.

The Anderson & Felix Guide to Naval Architecture (114 page pdf) is the shipbuilding bible for The Clement Sector. The book presents a ship design sequence that merges the adventure class ships from the TMB with Book 2: High Guard. Though not credited, I think even some of Adventure 3: Trillion Credit Squadron makes it not the tables. It also covers Small Craft and Pre-Granitic Drive spacecraft. My major criticism of this book is the lack of ship designs; indeed there is only one ship and one small craft presented.

The one interstellar polity in The Clement Sector is The Hub Federation. I purchased three Hub Federation-related items:

  • The Hub Federation (62 page pdf) provides players and referees background into the history, government, and worlds of the Hub Federation. Focus is on system details of the worlds. This is definitely an adventure-seed book for referees and an encyclopedic-reference for players.
  • Hub Federation Navy (95 page pdf) is the sourcebook for naval characters in the Hub Federation. Setting background specific to the Navy, including organization, uniforms, and fleet composition is provided. There is also an expanded chargen with additional career tracks . Surprisingly, though a navy-focused book, there is not one-single ship design in the entire product. GKG apparently is trying to get you to buy their Ships of the Clement Sector series instead. At least ONE design would have been appreciated!
  • Hub Federation Ground Forces (104 page pdf) is the sourcebook for army and marine characters. A little bit of flavor-fiction starts off this product, an item lacking in Hub Federation Navy. Like that product, history, organization, uniforms and expanded career tracks are presented. Unlike Hub Federation Navy, Ground Forces includes toys such as Assault Landers, a Strike Carrier (think marine assault ship), as well as vehicles and weapons. The addition of ships, vehicles, and weapons makes this a much more useful book than the navy one.

Taken together, these products are more than enough to start playing in the Clement Sector ATU. Although all the products have background and history, the level of detail is superficial enough to give referees lots of room to build their own setting within the broad brushstrokes GKG provides.