Archive for the Design system Category

Version 3.4.3 update

Posted in Boardgames, Design system, Intercept, Other vector movemet systems, Traveller on December 11, 2016 by Mr Backman

Board and counters

Vesta acquisition. In response to the verbal from the autopilot, Dieter Ulans flipped his datavisor in front of his eyes and prepared to take direct command of the massive ring of lasers and reaction engines that was Hercules. He hit the juicer button and felt the rush as the drugs began to wash into his veins. “Com’monn jockey juice!” he whispered and then began to croon: “All my thoughts of you, you, you — all that I’ve sought is you, you, you.” The tiny green symbols on the datavisor began to zip past his eyes at an increasing speed.

From the rulebook to Battlefleet Mars 1977 – Essentially the Expanse setting but 39 years before it aired.


There are lots of changes all over the rules, too many to mention. Sections have also been rewritten, gotten new or updated illustrations or have been rearranged, to clarify and simplify without actually changing too much.

As always, read the front page to get a feel how the game works. Then, read pages 2-3 which cover tasks and initiative, very important to grasp. From then on, simply start playing a turn and read as the turn progresses, the rules are written in turn sequence order.

You can download it all here, as usual, with the updated designs, maps etc.


The task system has gotten a facelift and a slight change to what Miss margins give what result. All tasks are now highlighted in red in the table columns to make them easier to find, they are also duplicated on the four reference pages at the back. All degrees of success or failure are now three points wide:

  • Very Good You rolled at least 6 points above the target number.
  • Good You rolled 3-5 above the target number
  • Fair You rolled 0-2 above the target number
  • Miss You missed by 1-3
  • Bad You missed by 4-6
  • Very Bad You missed by 6 or more 


The movement rules are basically the same as before but rewritten and clarified with step by step illustrations on how movement is performed. The section on plotting has also been clarified and with a detailed example illustration showing all aspects of plotting.


Fractional thrust Ships don’t come with Thrust in increments of whole Gs, fractions in increments of 0.25 Gs allow the ship an extra G on certain turns of every group of four turns. The mapsheet holds helpers for this and there is also check-boxes for fractional thrust, loaded and unloaded, on the ship Datacard too. All ready-made designs have these already filled in for you. A ship with 1.25 Gs of thrust would thrust 2 G on turn 1 and 1 G on turns 2-4, 2.5 Gs of thrust would thrust 3 G on turn 1 and 3 and 2 G on turns 2 and 4. A ship with 0.75 Gs of thrust would thrust 1 G on turns 1, 2 and 3 but cannot thrust on turn 4 of every group of 4 turns.

Free traderDatacard fractional thrusts

As damage to Thrust and Power affected how many Gs a ship could thrust this has been changed too, so you don’t have to recalculate what fractions to use as you get damage. Now Thrust and Power damage affects how many turns in a row you are allowed to thrust. All, 2 turns , 1 turn or not at all for No damage, Light, Severe or Critical damage. Plotting rules teach you to draw a circle around your ship whenever it drifts and thus reset the clock on thrust.


The fundamentals of the sensor rules remain the same, just clarifications and better examples. The only changes I can think of is that you no longer can use your Visual/IR and Radar sensors when popped in. On the other hand, ships may now pop in at any time during a turn as long as they haven’t used their weapons yet. Ships lose any tracked enemies and any launched missiles when popping in but as you know the vector and position on your targets when they were tracked reacquiring them should be fairly easy.

Oh, one more thing. Intercept now allow 2×2 scans, 2×2 square scans are +2 (+4 for radar), 2×2 boxes are -2 (-4 for radar). I didn’t allow them before because they didn’t have a clear center but showing where your scan is located should pose no problem anyway.

Map coordinate legend

The plotting rules now teached how to refer to boxes and sqaures on the map, using the legends on the map. To efer to the top left box of the map, say “Ay-one”, to refer to the bottom left square of the box where the latrge planet is in say “Dee-six one-five”. Always use column-then-row for the boxes followed by column-then-row for the individual squares.


The combat section has been rewritten and lots of die modifiers have been removed or baked into other rules. How much a ship thrusts no longer affect how hard they are to hit, we simply give a +2 DM on attacks, and defense when  drifting.

Underpower When a ship didn’t have enough power to use all their weapons when thrusting or drifting we previously used two DMs, peculiarly placed low on the Datacard and was often forgotten (I admit to cobbling it in wherever there was room).

Freetrader underpower ratings

Now, Underpower is one of All+, All, 2 turns, 1 turn, No fire, ships have separate Underpower ratings for Thrusting, Drifting or Jump prepping (more on that in the optional hyperspace rules). When a ship has Severe damage in its power location its Underpower rating is one level worse, All+ becomes All, All becomes 2 turns and so on.


Damage has changed considerably in this version. Ships now have only one DAB (Damage ABsorption) rating for the entire ship instead of one per location, ARM (for ARMour) is still per location and sometime even have two values, popped out / popped in for Surface damage, full power / silent running for high powered power locations representing their vulnerable heat radiators.

Penetration and Damage tables

How do we handle different damage at different locations then? We have three separate columns on the damage table, one for Hull, one for Crew, Core and Power and one column for Surface and Thrust.

Aerobraking & landing

I seem to rewrite the aerobraking and landing rules once every two weeks or so but now I have something that I feel I’m done with as it is fairly simple yet contains everything I want it to do. Docking and ramming has been moved to the optional rules as they tend to be used more rarely. I have increased the safe speeds for aerobraking somewhat so they become more useful. New illustrations and two examples help clarify things. there is even a little section dealing with your ships signatures when landed and how your sensors work through and atmosphere. Yeah, landing on the day side of a planet with atmosphere will make you harder to scan but your Visual/IR sensors will be blind from the bright atmosphere.

Optional rules

Campaign rules If you want to play a series of Intercept scenarios and have your crews and/or entire navy improving is skill from experience this is for you. The rules merely deal with how to track skill improvements but also skill loss from crew damage. There are also some bare bone outlines of scenarios to help you with ideas. This system is what we use at work when playing and interconnected series of space fights.

Redlining Have you ever wanted to pull all the safeties as captain Phillips did when Somali pirates tried to intercept him, or yell at your engineer ordering him to once again do the impossible? In other words, have you ever wanted to redline your engines?

You decide if you want a 50% boost to your thrust this turn or doubling it for a turn, the latter is of course more dangerous. There is a considerable likelihood that your thrust location will get a CD (Continuing Damage) ie ‘fire in the engine room!’ and you may even risk damaging your engine. Redlining, as well as powering up from silent running and the usual jury-rigging of battle damage is done by your trusty Repair Crew.

Jump distances for planets and asteroids

Hyperspace The rpg Traveller has a faster than light system that works by travelling far away from any planet, jumping into hyperspace, spending about a week there and exiting somewhere else parsecs away from where you started. I have shrunk how far one must travel to safely jump to fit planet and safe jump onto an Intercept mapsheet. There are some fairly detailed rules about how to jump, fuel use, astrogation, misjumps etc and where you will end up. In my system, all jumps have you end up somewhere, near a gas giant, planet or asteroid, even when you misjumped into an ’empty’ parsec hex in the original Traveller.

If you are playing a Traveller campaign I suggest you not only replace the space combat and starship movement rules with Intercept, replace the hyperspace rule too.

Design system

There are tons of changes to the design system too. Most importantly I think you get all the important design spec data in one place. As shown by this part from the Free trader design spreadsheet available in both InterceptBundle and Designs.

Ship stats for the Freetrader

Three little orange dots appeared on the screen. Look at him — blowing out decoys even though he knows we’re out of maneuver — that Kolnichok, grinned Dieter. So which one is you, Joey, and which are the aluminum balloons? (Seven dots grew on the screen, all had slightly different vectors.) Now you know my heater can take you in one flash and you also know that one zap is all I’m going to get. And if I take it you’ve got a perfect excuse to blow me up for the honor of the company rather than recapture valuable property for the accountants. So what’s it going to be? I think you shot off too many balloons too early Joey — cause the other ones aren’t making the course correction you just did. Ain’t that you, Joe?

Ulans squinted and tapped his foot.

From the rulebook to Battlefleet Mars 1977 – notice the green grid tactical maps where one could play out space battles with vector movement, in 3D no less, in 1977!


The contents of SPIs Battlefleet Mars boardgame from 1977.

Defense against missiles 101

Posted in Design system, Intercept, Rules on November 22, 2015 by Mr Backman

At 06:00 on 22 September, the weather had calmed and the ships were patrolling at 10 knots, line abreast, 2 nmi apart. Lookouts were posted for submarine periscopes or ships and one gun either side of each ship was manned. U-9 had been ordered to attack British transports at Ostend, but had been forced to dive and shelter from the storm. On surfacing, she spotted the British ships and moved to attack.

At 06:20, the submarine fired one torpedo at the nearest ship from a range of 550 yd, which struck Aboukir on the starboard side, flooding the engine room and causing the ship to stop immediately. No submarines had been sighted, so Drummond assumed that the ship had hit a mine, and ordered the other two cruisers to close in to help. After 25 minutes, Aboukir capsized, sinking five minutes later. Only one boat could be launched, because of damage from the explosion and the failure of steam-powered winches needed to launch them.

U-9 rose to periscope depth from her dive after firing the initial torpedo to observe two British cruisers engaged in the rescue of men from the sinking ship. Weddigen fired two more torpedoes at his next target, Hogue, from a range of 300 yd. As the torpedoes left the submarine, her bows rose out of the water and she was spotted by Hogue, which opened fire before the submarine dived.

Livebait squadron of September 22 1914

Image by Rob Caswell

Missiles are deadly in Intercept, especially those with the Cold start option that are really tricky to detect when drifting. The controlling ship may be far away and unlike beam attacks, the attacker isn’t giving himself away when attacking. So, how does one go about reducing the risk of missile death?

The basics

Missiles move last, after all ships have moved. They are still moved in reverse Initiative order but after all of the ships has done the same. Small missiles typically have an endurance of 15 minutes which mean their range is limited to the distance from the launching ships Drift and you. This means that if your ship is beyond 6 squares from the attacking ships Drift, no unmodified small missile can hit you. Safe, assuming they are not modified, assuming you track the enemy ship and thus know its Drift position, lots of assumptions.

In reality you may have a hunch on from what direction a missile attack will come from, based on the scenario. Always make sure you have lasers covering that direction through their attack arc, and make damned sure your aft centerline isn’t pointing towards the threat direction.


If the enemy is Tracking you, you might as well use your Radar. Setting a 1×1 square Radar Scan on top of your ship gives a +6 in Scan strength and small missiles have a Radar signature of +2. This should almost guarantee that any missile will be Tracked before impacting, so you avoid the -3 DM for defending against unknown attacks. As Intercept only allow two Scans per side per turn this isn’t practical for many dispersed ships but keeping them in close formation might help.

Cold start missiles

Cold start missiles sacrifice 2G for the ability to thrust and drift as they please. This means that a TL 14+ small missile will have 4GTurns of total fuel to maneuver with, larger missiles still have the 4G limit but have better endurance for larger amounts of GTurns. Keep changing vectors of your ship so the unseen Cold start missiles of your enemy must expand precious GTurns to keep up. Perform large IR Scans to see if you can catch a Cold start missile thrusting, a small missile thrusting have an IR Signature of +6 and even if you only get an Indication, you’ll know it’s out there.

Matching vectors

Matching vectors completely is well-nigh impossible but try at least to avoid having a relative vector of 5 or more as this give the missiles +6 on both PEN and DAM! Sure, they also get a -2 DM to hit but do you really dare risking that? Your defense rolls will suffer the same -2 DM too.


Make sure your design have laser turrets on both left and right or both top and bottom. This way at least one will always bear. Large warships can take a lot of damage even from missiles but are still smoked when hit by nukes, add nuclear dampers too in that case. You are allowed two defense rolls against nuke missiles; one from lasers and the other from dampers. As results stack this is pretty effective against the threat of nukes. Two Fair results from lasers and dampers would require the missile volley to be VGood to still hit.

In Traveller, civilians and now allowed to have dampers but then again, neither are they allowed to have nukes. Even pirates usually avoid nukes as they tend to destroy the precious ship and cargo and then they’ll have the Imperial Navy on their ass as nukes are certainly a breach of the Imperial rules of war. Pirates with nukes rarely end up in court, they usually end up dead.

Page 41 cover the basic parameters of missiles and all the options to modify them, except the nuke option which is covered in the optional rules section page 23. Missile parameters are also duplicated on page 45 of the tables section at the back of the rulebook.

Subsidized merchant DataCard

Posted in Design system, Intercept, Rules with tags , , , , on December 1, 2013 by Mr Backman
Image courtesy of mr Ian Stead

Image courtesy of mr Ian Stead

“What a piece of junk!” – Luke Skywalker
“You came in that thing? You’re braver than I thought.” – Leia to Han 
“Would it help if I got out and pushed?” – Leia to Han
“It might!” – Han to Leia
“She’s the fastest hunk of junk in the galaxy.” – Lando Calrissian

Subsidized merchant DataCard

I have updated the DataCard and Intercept rulebook, get ’em while they’re hot, at the downloads page 2013-12-01

The design system holds everything there is to know about your ship but to use it for an Intercept space battle you need to fill in its DataCard. The DataCard holds all data crucial to space battles where the Ship.xls hold everything there is to know about the design. Print out DataCard.pdf and fill in your designs. We will use the Subsidized merchant as worked examples on how to fill in the DataCard. There is a ready-made Subsidized merchant and Launch document in the and eventually I’ll fill out the rest of my designs. OK, let’s get on with the worked example shall we. The little thumbnail above is the entire DataCard but I will break it down into pieces a comment on each part s it gets filled in. As always, go to the downloads page to look for the latest version of everything – the rules, the design system and sometimes also the DataCard may all get updates now and then.


First we write the ships name at the top left of the DataCard. To the right of the name we see some rows of checkboxes. The one labeled Turns can be ignored as it is used by the Deterministic optional rules indicating how many steps of turn the ship has for each of the four turns. The row labeled AB Initiative side A check the odd boxes and side B check the even boxes. These are used for tie breaking Initiative. The lowest row of boxes labeled Frac thrust is where you check the turns where your fractional thrust gives you an extra G. Look up Fractional thrust in the rule book for details, our Subsidized merchant happens to have  no decimal thrust when loaded or unloaded so we leave them unchecked.


To the right is a box for Size; +8 for our example. This is the target number for all Pilot rolls (and a Tactician rolls too, however unlikely in a Subsidized merchant).The Comp# box should hold your computers model number. Make sure there is room for the computer dice pool. These can can be used to improve all Pilot, Tactician, Attack, Defense, Sensors or Repair roll by rolling one or more dice from the pool and picking the two highest D6, every four turns the computer dice pool is replenished by the current Model #. We write 1: for our Model-1 computer. To the right of that are four boxes were we write the beam to-hit numbers for 1, 3 and 10 squares range and the missile to-hit value, all taking our ships Size into account. Look up the numbers and subtract Size to get your ships target numbers. These are the base numbers your enemy roll against to hit your ship. We write 4+, 7+, 10+ and 6+ respectively.

Write your ships Thrust Gs (Loaded/Unloaded)  in the Thrust box.  The last box in the top row, the Fuel box, holds how many GTurns worth of fuel the ship has, loaded/unloaded. The box is large enough for you to tick off fuel use when playing. Only ships with Fission or Fusion thrusters have this value, Impulse drives expend no fuel when thrusting and neither does a Floater, our ship write 10/20: here. Yes, the sub is known for its extremely low delta-V, that old-timer who belittled the sub crews has obviously never flown one as their low delta-V requires careful planning and experience.


The next row should hold the ships Streamlining type; Open frame, Normal, Streamlined or Airframe, also add the areobrake damage modifier for speed here. The name of the streamlining should be entered but also the damage modifier for speed which is important when doing areobrakes or landing. The damage per speed modifiers is from the areobrake table in the rulebook, in the section on planets.

  • Open frame The ISS or other irregular structures. +6/1 speed but you shouldn’t really do any areobraking with these. If you areobrake facing is off by two or more your first speed brake will be treated as Open frame. Hulls with Critical damage are always treated as Open frame.
  • Normal A car or a subsonic aircraft. +3/1 speed. If you areobrake facing is off by one your first speed brake will be trated as Normal unless it is Open frame. Hulls with Severe damage are always treated as Normal or worse.
  • Streamlined A jetfighter or the space shuttle. +1/1 speed. This is the minimum streamlining for reasonably safe areobrakes and atmosphere landings. Hulls with Light damage are always treated as Streamlined or worse.
  • Airframe The SR-71 or other extremely streamlined hypersonic designs. +1/3 speed. Areobrakes and atmosphere landings are safe unless your facing is off or brake more than your frame can handle.

We write Streamlined +1/1 and 7% 1 for the percentage of wings an extra areobrake (1 for every full 5%). Wings is only used for aerobraking in Intercept but may be more important in roleplaying situations, especially for the Subsidized merchant.


Below this there’s a large box where all the ships Signatures should be entered. If your battle takes place where the Sun factor is not +6 you should enter the actual value to get properly modified Signatures. Remember that if the Sun factor is, say +5 you should subtract 5 from Visual(Hull) when the ship is in the Shadow column, instead of the usual 6. Note the Sun factor at the top of your map sheet as a reminder.


The box with the ship status check boxes can be ignored as they are only used in-game to indicate status changes, I’ll show you their picture anyway.


Below that there are some boxes for the Sensitivity of your sensors. We enter -1 for our Optical (Visual/IR) and -5 for our small radar. Note that radar Scans are the only ones using any significant amounts of power.


To the right of this we have the crew box where the numbers and special notes of our crew are entered. We write 1 Pilot, 1 Astrogator, (2) Sensor ops, 3 Gunners and 2 Techs. The parenthesis around the Sensor ops value indicate that Gunners and Sensor ops serve dual roles; if any attacks or defense-rolls were made in a turn we get -2 on our Scan factor as the same crew members were doing both tasks.


To the right of this there’s the hit location box where damage, continuing damage, jury rig repairs and frozen watch revival is tracked. There are also check boxes for the current location of the repair crew. Enter the ARM and DAB values for you design here. The Subsidized merchant has these values: Hull +20 ARM +25 DAB Surface +15/+17 ARM +19 DAB Crew +20 ARM +22 DAB Payload +20 ARM +22 DAB Power +20 ARM +22 DAB Thrust +17 ARM +19 DAB The Surface part has 4 check box rows for Top/Front, Left, Right and Bottom/Rear and should be applied damage based on what facing the attk came from. The Power part may have two values; the left for full power and the left when Silent running, only ships with vulnerable radiators have two values there.

The column of check boxes labeled RC tells the current location of your Repair Crew. Check its location whenever it moves to a new location,Repair Crew takes the same damage when that location is hit. To the right of the RC column there is one labeled JR which stands for Jury Rig. Jury Rigged locations are treated as having one level less damage for damage effects purposes.

The check boxes labeled L, S, C and D are used for the damage level of a location and they stand for Light, Severe, Critical and Destroyed. Damage to an already damaged location work like this:

  • New damage level is higher Replace the old damage with the new, uncheck JR but CD remains.
  • New damage level is equal Add one damage level, uncheck JR but CD remains.
  • New damage level is lower Keep the old damage level, uncheck JR but CD remains.

The CD column stands for Continuing Damage which is damage that may get worse over time, like fires and the like. A hit gets Continuing Damage if the Damage roll turned up as a 6. Each turn, after repairs and if repairs failed, roll a D6 per CD; 1 and the CD is removed of itself, 2-4 has no effect and 5-6 increases damage one level. If a non-Hull location gets Destroyed from CD remove the CD there and add a CD to the Hull location, even if the Hull is completely undamaged. A Destroyed Hull, as you can imagine, destroys the ship. Yes, a tiny hit in the Surface location can, with lots of sheer luck, eventually destroy the entire ship.


The three boxes labeled Volley A – C are used to note endurance expenditure for missiles with longer endurance than one turn. If more than 3 volleys are in flight at the same time simply note this on a separate piece of paper. Below all is the area for weapons and mounts.


The right part holds the number and types of various weapon. Sand casters, Meson screen and Nuclear dampers write their ARM values in the PEN column and missiles treat the Range column as the controller range. Our Subsidized merchant has two sand-casters, two lasers and two missile launchers, one for each of the two large turrets mounted  Left and Right.

The right part holds the mounts of the ship and their respective locations. Our ship has 2 Large Turrets mounted on the left and right, each with one Sand-caster, one 10 MW laser and one Small missile launcher.

It should be self-evident how this work for your own designs. Note that different missiles can have different parameters and a ship may carry more than one kind so all variants should be noted so somewhere and each volley clearly noted what type it holds. A single volley can only hold one type of missiles but the launcher can choose which type it launches, even from a magazine.

Well, that is all folks. Look at the Lauch values and see if you understand how that design is put together. Note that the Small turret mounted on top is NOT standard issue but a modification done for my daughters Launch and can be a pretty nasty surprise to anyone believening that the Launch of a Subsidized merchant is harmless.

Custom crew

Posted in Design system, Intercept on November 17, 2013 by Mr Backman
Nostromo Crew courtesy of

Nostromo Crew courtesy of

Crew? I pilot the ship, I astrogate for hyperspace, I scan with my sensors and if I see something I don’t like, I shoot it with my lasers. Repairs? Hah, my ship is too scared of me to ever break down.

Sir Charles Pancroft, Baron of Centry, on the merits of a one man ship crew.

Centry/Glisten/Spinward marches 023-1013

Custom crew example

Intercept make various assumptions regarding crew size which may not fit your concept of how the ship should be crewed. As an example, Intercept assumes that Gunners and Sensor ops hold dual roles (the lower number of the two is in parenthesis to indicate this). Write your own value, including 0, to override whatever Intercept has calculated. I have added some smarts to the design sheet to help you see what effects your crew numbers will have:

  • Tactician (Pilot) The ship is small enough that the Pilot and Tactician can be the same person without penalty. Instead of using the lowest result of the Pilot roll and the Tactician roll he simply roll once using the lowest skill of Pilot and whatever flavor of Tactician skill he uses (Ship tactics or Fleet tactics).
  • Sensor ops (2) Sensor ops or Gunners crew number in parenthesis indicate that Intercept assumes the two positions are dual-role. If you intend to Scan after combat your attacks and defenses are modified by -2 and your scans are also modified by -2. If you want dedicated Gunners and Sensor Ops to avoid penalties from dual role simply write the number in the light yellow edit column to the right.
  • Gunners (-2) A negative value in parenthesis after the crew type is your Undermanning modifier, ‘(No)’ means you cannot perform tasks by that crew category  because you have less than 10% of the required crew.
  • Technicians (No FW) A ‘(No FW)’ means your Repair Crew must be repaired instead of revived by Frozen Watch because it has more than 50% robots.
  • Low passage? A ‘?’ indicate that you don’t have enough freezers for the numbers you have chosen.
  • Total crew? A ‘?’ indicate that you don’t have enough life support units for the numbers you have chosen.
  • Frozen watch (x2) A ‘(x1)’ or ‘(x2)’ after Frozen watch indicate how many levels of damage you can restore from Frozen watch. You can never have more damage level restores than 2 no matter how large frozen watch you specify.

The design system and ready-made designs have been updated as has the rule book (look at the top row for Ship.xls version and Data.xls version. Ship.xls version should be 2013-11-17 or newer). You can download them all from the Downloads page.

Q: What do you call a timepiece that stops whenever the temperature goes below zero?

A: The frozen watch.

Intercept 3.3 update

Posted in Design system, Intercept, Rules, Traveller on November 10, 2013 by Mr Backman

Laser with mirror

Yeah, it is true, I finally managed to put it together and get it ready to download. there are lots of changes, rearrangements and tweaks, too many to mention all so I will just give you the major points. I have scattered some illustrations here and there in the rules to liven things up a bit and to exercise my limited artistic abilities.

Download the latest version of Intercept and designs from the Downloads page.

Design system

The design system has gotten some changes here and there but now for the first time there is actual documentation on how to design ships in the rulebook. This part is placed at the end, right before the tables and charts, so you can print out the Design rules in a separate booklet if you like.


There are many changes to how ships interact with planets and these changes are reflected in the new mapsheets. There is one sheet with a small planet in the middle, one with a large planet and also one where a large and small planet are placed far apart to play out scenarios in the Earth – Moon neighbourhood. The mapsheets are now included in the Intercept bundle.

Missile customization

Various missile customization options are tabulated in the rules but maybe not too deeply explained. Read about missile customization here.


Planets have their own section now with rules on planetary line of sight, gravity etc in one place instead of scattered throughout the rules. The rules for stable orbits now cover polar orbits as well.  The planetary line of sight rules and sun shadow rules have changed considerably so make sure you read up on planets if you use them in the game.

Consolidated Pilot task

A fancy name for the section where various Pilot related stuff is located. You will find rules for docking, ramming, landing on planets, crashing into planets, voluntary and mandatory areobrakes etc. This section is a good place for a Traveller referee to get less ad-hoc and more believable rules for ship to ship and ship to planet interaction with more choices and participation by the players while still taking the characters skill into consideration.

Traveller integration

A page on how to integrate Intercept with Traveller has been added, to be filled with rules and tips whenever someone actually bothers to give me feedback. For me, Intercept is Traveller so I see no real point in writing conversions for various Traveller versions, the most likely one to get this treatment will be the Mongoose version of Traveller which I like in many ways, mostly for its adherence to the original LBB version. Just subtract 1 from your Mongoose or Classic Traveller skill level to get the D to use in Intercept, GURPS players should use (skill – 10) / 2.

Custom missiles

Posted in Design system, Intercept, Rules on November 1, 2013 by Mr Backman

Missile schematic

Isn’t it a drag that regular 50 kg missiles endurance is only 15 minutes? One measly turn of full thrust. Wouldn’t it be nice to have missiles that start drifting and can be turned on when they are close to their foe. What about decoy missiles that mimic your ships signature? Frag missiles, missiles with sensors, longer range controllers, higher thrust missiles, the list goes on and on.  What if you could custom build missiles to your own specifications?

I am in the process of rewriting Intercept for its 3.4 release with some major changes in the pipe I though I should give you its custom missile rules as an appetizer. These rules will work with the old as well as the new, upcoming rules. So, without further ado, here comes the custom missile rules. Updated Design system, Rules and Maptemplates are available here.


Misslles in Intercept are operator guided from the launcher and comes in three sizes;

  • Small missile. 50 kg with 15 minutes endurance. They are sometimes called rockets and are all fission powered, they the only legal missile size for private ships.
  • Medium missile. 500 kg with 30 minutes endurance. They are sometimes called torpedos, fission powered at TL 9- and Fusion powered at TL 10+.
  • Large missile. 5000 kg with 1 hour endurance. They are sometimes called heavy torpedos, fission powered at TL 9- and Fusion powered at TL 10+.

The standard capabilities of missiles can be seen in the following tables (which are also in the rulebook and will shown on your ship designs as well.

Missile tables


The above basic missile parameters can be modified to achieve certain goals. Most modifications alter the Thrust Gs of the missile and can be seen as modifications of the final dry mass of the missile. Modifications cannot modify the Thrust Gs to less than 0 and if modified down to 0 the missile will drift only, useful for decoys and sensors missiles but not much else. 0G missiles cannnot attack ships, even if they land on the same square as a target, a 10 000 km square is pretty huge after all.


  • Half endurance (+1G, x1/2 endurance)
  • Double endurance (-1G, x2 endurance, x2controller range)
  • Triple endurance (-2G, x3 endurance, x3controller range)
  • Quad endurance (-3G, x4 endurance, x4controller range)

Endurance modifications affect how long the missile can thrust, smaller engine leaves room for more remass and vice versa. Missiles endurance will start ticking as soon as they launch regardless of endurance. If you want to launch them drifting you must add the Cold start option below. Double, triple or quadruple endurance also affects Controller range with the same multipliers, half endurance does not reduce controller range.

Cold start

  • Cold start (-2G, double price)

Normally it is the launcher that starts the engine for the missile but if you want to launch your missiles driftig you should add the Cold start option. Cold start does not allow you to turn on or off the missile at a whim, once started the engines cannot then be turned off and they will continue to burn until their endurance limit is reached. Cold start option doubles the price of the missile.


Frag missile (PEN-6, DAM-6, +3 DM)

If you want your missile to fragment before hitting thus increasing the hit chance at the expense of penetration and damage you should consider the Frag option. Giving a missile the frag option does not modify Thrust and does not affect price, it merely changes how the missile deals damage. Frag missiles are favorites among pirates as they can easily take out weapons and sensors of a ship (making them blind and defenseless) without unduly damage the ship and its cargo.


  • Vis & Radar decoy (-1G per +2 Vis & Radar)
  • IR decoy (-1G per +2 IR x4 drift endurance)
  • Neutrino decoy (-1G per +2 Neutrino x4 drift endurance, double price)

Decoy mods come in three varietys Visual & Radar, Infrared and Neutrino. There is no way to alter a missiles Mass signature, not at the Tech Levels Intercept deals with (6-16). Visual & Radar decoys are metal foil balloons, IR decoys are burning magnesium or thermite charges with the appropriate oxidizers, Neutrino decoys are short halflife radioactive compunds that mimic regular powerplants or thrusters. Decoy modifications really does nothing more than increase the signatures of the missile. IR and Neutrino decoy modifications run 4x as long as the missiles endurance and but they go online at launch like all decoy mods, even if the missile has the Cold start option. After the IR and Neutrino decoy mods have lasted their endurance the missile goes back to its regular, pre modified, signatures. Visual & Radar modifications are always on and have unlimited endurance.


  • Sensor(-2G, double price, Vis/IR rating from table below, double controller range)

Missiles can be equipped with low powered Visual/IR sensors so you can do your sensing from the missile instead of your own ship, this may help you scanning near planets or avoid performing Scans with Sun blinding. Missiles with sensors must be within Launcher range and arc at all times as does all missiles. THere is no endurance limit to sensors, they may start sensing as soon as they are launched regardless if the missile has Cold start or not. The acual sensors Sensitivity value comes from the table below:

Missile sensors

Launcher range

All missiles are operator guided and have a maximum range that depends on the missile type and TL of the launcher. Missiles beyond this range are auto­matically lost. Launcher range is based on missile size and TL but is also multiplied by Endurance modifications and the Sensors option. Note that half endurance missiles does not reduce launcher range.

Launcher ranges

Missile price

  • Cold start (price x2)
  • Neutrino decoy (price x2)
  • Sensor (price x2)

Small missiles cost 10 000 Cr, Medium missiles cost 100 000 Cr and Large missiles cost 1 000 000 Cr.

These prices are modified for some of the options above which should be all multiplied together to get the final price of the missile. Note that the Neutrino decoy option will only double the price once, regardless of how many levels of Neutrino decoy you give the missile.

Well, that is all for now folks, and remember; it is not the missile that kills you, it is the sudden stop of the missile.

Changes to Intercept

Posted in Design system, Intercept, Rules, Traveller on April 8, 2013 by Mr Backman

Some of you may not know it but I keep doing updates to the rules, maps, datacards and design system on a regular bases, just download the Intercept bundle here. Quite a lot of updates have accumulated without andy update posts but I will try to summarise the most recent changes below. To see what version you have simply look at the headings row of the design system for version date. I always update Ship.xls and Data.xls in tandem.  You can see the version of the Data.xls where you see the Ship.xls version number.  To update your designs you need to copy each column labeled Edit from your old design and paste* it into the new Ship.xls, then close the old design and save Ship.xls as the old designs name overwriting it. When you paste it is much safer to do the Paste->Paste values to ensure that you won’t overwrite and formatting.

Updating the Ship.xls sheet

All kinds of thrusters now correctly reports their actual thrust, the two values are Loaded / Unloaded performance. The Mtrl type field now goes from 0-3 with ever decreasing masses for most of a ships components. If you find your designs too low in acceleration and delta-V you should increase your material types to lighter but more expensive versions.

Editable Sun factor

Sun factor
There is now a light yellow field for the Sun factor. It should be easy to recalculate Vis(Hull) and IR(Hull) for other values of the Sun factor but now you can simply enter the value you want in the yellow box. Sun factor is +6 in the life zone of a solar system and goes up by 1 for each orbit inside and down by 1 for each orbit outside down to Sun factor 0. Mercury is +8, Venus is +7, Earth and Luna is of course +6, Mars is +5, Asteroid belt is +4, Jupiter and its moons are +3, Saturn and its moons are +2, Uranus and its moons are +1 and Neptune and its moons are 0. Pluto isn’t even a planet but as its orbit is never much closer than Neptune it is always 0 in Sun factor. Ships in Planet shadow subtract the Sun factor from Vis(Hull).

Living space
Living space and Life support determine the quality of life for the crew past the endurance of its crew stations. More living space per crew member means longer trips without physical or psychological effects. This is mostly here for roleplaying uses but if you design your own ships for competitive play make sure yiu stipulate the expected trip time requirements, ships using Jump drives should have at least one week endurance as this is the time the ship spends in hyperspace. Note that the Closed Lifesupport option requires lots of room for the green house but that entire volume is also treated as Living space and this is reflected on your ship designs.

Living space and crew comfort table

  • 1 m3 per crewmember Cramped 1 day cruise
  • 2 m3 per crewmember Normal 1 day cruise
  • 5 m3 per crewmember Roomy 1 day cruise
  • 10 m3 per crewmember Cramped 1 week cruise
  • 20 m3 per crewmember Normal 1 week cruise
  • 50 m3 per crewmember Normal 1 month cruise
  • 100 m3 per crewmember Cramped 1 year cruise
  • 200 m3 per crewmember Normal 1 year cruise
  • 500 m3 per crewmember Roomy 1 year cruise

Well, that is all for this update, more to come regarding the rules changes later (when I will also document the polar plane gravity sling stealth manuver sometimes called the Marre Red).