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.

Asteroids and maintenence update

Posted in Intercept, Rules on November 20, 2015 by Mr Backman

Image from

“Asteroids do not concern me, I want that ship” – Darth Vader

If you know how to play Intercept already you may skip to the last section of this post, dealing with the newly added Asteroid rules.

The rules have been rearranged slightly to make them easier to learn bit by bit.  The best way to learn these rules quickly is either play with me, I’ll gladly teach you but not everyone live in Uppsala, or even Sweden for that matter. Ask questions here on the blog may also work of course. Another way to learn the rules is that you alone or with a friend try to play a test game. Start off by flipping through the booklet getting a feel for what’s in there, lots and lots of tables, diagrams and text with boldface lines sprinkled here and there. Daunting? Not to worry, the rules are structured in such a way that you can read the rules and learn each stage as you read.

Sequence of play

The first page hold a fairly detailed summary of the sequence of play. Yeah, the black page with a space battle barely discernible behind it and that cool Intercept logo tilted 90 degrees like some kind of layout pro made it, that page. Read this page carefully but you really don’t have to understand it, just familiarize yourself with the order of things. Note that all players do each step in parallel, there is no I-move-shooot-inflict-damaga then You-move-shooot-inflict-damaga.


First you read page 2-3 that tell you have to resolve tasks with dice rolling and how the Initiative system works ie in what order within a phase the players perform things. When you have determined Initiative (rolled 2D6 and noted the result, various tie-breakers handle when both rolled the same result. OK, Initiative is determined now go on to movement. Read page 4-5 on movement and perform the movement step by step where low Initiative goes first, then high. If you like you can skip the hidden movement and sensors aspect of the game to make it simpler, just assume that both ships have Tracked result on the other so there’s no need for secret plotting etc.


If you want to do the Sensors phase you should read  page 6-7, not that only the first Scan target question need be asked if there’s no planet or asteroid on the map, the question “Does your Scan touch your´ship’s Sunglare column?”. OK, follow the Sensor rules, roll Sensor tasks for getting a tracked result etc. Remember that you don’t have to do this the first time you play but do come back to it later as it is the secret plotting and Sensor rules that set Intercept apart, creating that submarine feeling lacking in all other space combat systems.


If the ships are close enough for combat you should read page 8-9 for the general procedure of combat and page 10 and 11 for beam combat and missile combat respectively. If you hit and defenses such as sandcasters against lasers, lasers against missiles completely stopped the attack you continue with damage. Page 12-13 tell you how to do hitlocation, penetration and damage. Page 14 explains what effect damage has on the ships six hitlocations and 15 finally explain how you repair damage using the Repair Crew. This is the end of the basic game and all tables as well as important figures are doubled on the last four pages.


The last four pages could be printed double-sided as each side is used for one distinct part of the game, print one set of these per player. The few tables with gray headings are only used in the optional Deterministic rules (yeah, no random elements at all if you’ prefer that but learn the basic game first).

Page 45 holds data on weapons, missiles and sensors but these are already filled in on the ready-made data cards. If you made your own ships these values will be calculated for you and all you must do is fill them in on a blank Datacard, this page is rarely used.

Page 46 holds tables and figures on Task determination (rolling 2D6 vs a number with a bunch of modifiers), Initiative, Movement and Sensors.

Page 47 holds tables and figures for combat, attacks, defenses etc.

Page 48 finally holds the tables and figures for Hitlocation, Penetration and Damage, Damage effects and Repairs.


This is straight from the rulebook page 22, at the end of the Planets section, jus before the optional rules begin on page 23.

Small asteroid
Small asteroids are at least 1 km in diameter but less than 100 km. Their mass is too low for any significant gravity, ships can Mass Scan to or from Small asteroids without penalty.
The only planetary LOS rules are for their Sun column of infinite length and their Shadow column of 1 square.

Large asteroid
Large asteroids are at least 100 km in diameter but less than 1000 km. Their Mass is high enough to forbid Mass Scans to or from them, look at the next section for gravity effects when calculating Drift in the same square as an large asteroid.
The only planetary LOS rules are for their Sun column of infinite length and their Shadow column of 5 squares.
Asteroid gravity and movement
Asteroids, large and small, behave like ships when you enter the same square as them. You cannot accidentally crash into them, asteroids cannot crash into other asteroids, but they can crash into planets but players cannot alter the vectors of asteroids their course will be predetermined from the start of the scenario.
Asteroids move as drifting ships, they have vectors, calculate Drift just as normal and ships landed on the follow along. They are also affected by gravity in the same way, to model Phobos or Deimos of Mars, just have two small asteroids in orbit around a Small planet.
Large asteroids have a small gravity field affecting their square itself. Ships that was not landed have their Drift moved into any adjacent square if the ship is Piloted, or their fwd square if unpiloted, (landed ships are never affected by gravity except being forbidden to Mass Scan). A ship is unpiloted if it has a Hull damage of Critical+, a Crew damage of Critical+ or a Thrust damage of Critical+.
Landing on asteroids work the same as for small planets; chose whether landing in the Sunside or the Darkside, see the Landed or Docked signatures and Scans on page 17.

Asteroid LOS
Asteroid LOS procedure is simpler than for planets.
Ask if the Scan touches the Sunglare column and if yes reduce the Scan by -6 (Sun). This rule always apply, even when neither planets nor asteroids are on the map.
If a Scan touches the Sun column ask if the Scan was from the Shadow column and if yes ignore any targets in the Suncolumn.
If a Scan touches the Shadow column ask if the Scan was from the Sun column and if yes ignore any targets in the Shadow column.

Special sensors
The above rules on Sunglare, Sun column, Shadow column all apply to the Visual and IR Scans, other sensors have certain restrictions.
Radar Ignores the Sunglare rules, all other above rules apply.
Neutrino Ignores all asteroid LOS rules except Sunglare.
Mass Ignore all asteroid LOS rules as well as the Sunglare rules. Mass Scans are illegal to or from large asteroids. Yes, ask if a Mass Scan was to or from a large asteroid.


Posted in Intercept on November 11, 2015 by Mr Backman

Sentinel field of view

Image credit: Bell Aerospace / B612 Foundation.

‘Keep the solar wind to your backside’, isn’t that just a clever way of explaining how to attack from out of the sun, Baron Richtofen style?

Some players, mainly my kids, have complained that the rules on Sunglare is too harsh. If your Scan touches the Sunglare column (the column of squares from your ship straight up towards the central star) is reduced in strength by -6 (or Sun factor really, but that is typically 6).

Well, it so happens that a proposed satellite to scan for asteroids have much more severe limitations on where they may Scan as the picture show. No, I promise I won’t make it any harder to Scan towards the Sun, I’ll keep it the way it is, just a friendly reminder that Intercept is actually nicer and more forgiving than the cold equations of physics. The picture is from an interesting article that you may or may not agree with, dealing with the costs and benefits of deflecting asteroids.

Indication, Contact and Tracked

Posted in Intercept, Rules on October 29, 2015 by Mr Backman

Ensign Murphy checking scan results

The sensor data told me something was out there in the sea of noise, something too weak to distill out. I decided to keep my sensor integrating, what you mudballers call a longer exposure. After keeping the visual scope open at the same patch of sky for an entire hour my hunch turned into real, a blip condensed out of the noise. No tracked target yet, but if we saw it more than once we could start guessing its future position and narrow our scans for better signal. Yep, after another hour we had him, tracked hard and no more guesswork as to what he was about to do.

How does this integration work you ask, doesn’t the noise rise as fast as the signal, twice the noise and twice the signal is the same, right?

No, noise is random, signal is not. Let’s say you have a hundred dice all rolling as they should except one that always roll a six. Roll all dice once and you’d get around 17 dice turning up six. Roll again and about three dice will have a sum of 12, one of them being the crooked die. Very soon you’d end up with just the crooked die, the one always rolling a six, the signal.

In Intercept we simulate sensor integration by giving the player a +1 for each previous consecutive identical scan up to a maximum +3. Identical meaning same size, position, sensor type, position and, most importantly, the same ship. This is rarely done with your original scan gave you not even an Indication but it is perfectly legal, just remember that your ship must be stationary. Scan + Signature = Signal which is what determines what you get to learn from the target.

Consecutive Identical Scan

All of these rules must be obeyed to get a consecutive bonus of +1 per turn, up to the maximum of +3.

  • Same Scan position
  • Same Scan size
  • Same Scan type
  • From same position
  • From same ship

-1 Signal or worse: Nothing

The target player tells you nothing, not even whether something was there or not, just silence. Sneaky players take their time answering this, asking again about the Scan strength etc, to make it harder for you to guess whether something with too weak a signal was there or just nothing at all.

0-2 Signal: Indication

Target player tells you only that something is there within your Scan, implicitly telling you that the Signal was 0-2. You can either guess at where in the Scan it really was located and start doing smaller Scans to get better Signal, or keep doing the exact same Scan to get that +1 per turn up to +3 for consecutive identical scans.

3+ Signal: Contact or Tracked

Target tell you its signature and what kind(s) such as Visual(Hull) etc, target will also tell you its position, but not vector. Target my now roll a sensor task to see if he can get a Tracked result or not. Roll 2D6 plus various modifiers (Crew damage, dualrole from previous Pilot task by the same crewmember etc). The task result determines what Signal is required to get a Tracked result.

Sensor task result

The sensor task result tell you what Signal is required to get a Tracked result. You will always need at least 4 but the worse your task result is the worse the required Signal become. If you miss the task roll you must get a Signal of 12+! Yes, Sensors may get a Tracked result automatically without a Crew doing the task, if the Signal is high enough.

VGood Signal 4+ is required to get a Tracked result.

Good Signal 5+ is required to get a Tracked result.

Fair Signal 6+ is required to get a Tracked result.

Miss Signal 12+ is required to get a Tracked result.

Tracked result

When a target is Tracked you will learn what kind of target it is, its vector, facing and rolled status, popped in or not, Silent running or not. Until Tracked status is lost he will do his movement on the common map before you make your own, so you can see exactly how he moves and act accordingly. An untracked ship always win Initiative against a Tracked one. For a ship to lose its Tracked target it must; have Crew or Sensors Critical or worse damaged, have a tracked target blocked bu planet LOS, have its target in the aft centerline or having its target beyond the Max tacked range table. Defending against attacks from untracked enemies, ships or missiles, have a penalty of -3 to defense rolls. Beam attacks may learn the position of the attacker under certain circumstances as follows (from page 16 of the rulebook).

Target learns attacker position if the target still have a working Optical sensor after the attack

Particle accelerators
Target learns attacker position if the target still have a working Optical sensor after the attack

Meson guns
Target learns attacker position if the target still have a working Meson screen after the attack.

That is all folks, next time I’ll talk some more on the new stuff in version 3.4.2. Keep the solar wind to your backside!

Version 3.4.2 ready

Posted in Intercept, Rules on October 25, 2015 by Mr Backman

System Defense Boats. Looked down upon by the Imperial Navy with their huge warsships and noble heritage. Yet the local defense by the SDBs is essential as it locks up forces to guard already taken systems. The SDBs hide on planets with atmospheres, on asteroids in the belts or inside the atmospheres of gasgiants. There they stay, for months, waiting for an opportunity to strike back. Lacking jumpdrives, an SDB always outgun a warship, ton for ton or Megacredit for Megacredit. This lack of jump capaility is also their achilles heel, they rely on fragile Jumpshuttles to ferry them outsystem or to rotate their crews.

3.4.2 changes

Well, I have been busy haven’t I. Lots of large and small changes in the rulebook and designs. Aerobraking, landing, crashing, taking off, ramming or docking have been updated and clarified. A ship’s signatures and scan changes when on a planet, asteroid or hovering in gasgiant atmosphere have been added. Lots of little changes here and there, updated designs and design system to make Visual(Hull) and the effects of being in sunshine or darkness are in, all ready ship designs updated.


Scan procedure

At the sensor phase of each gameturn players take turn calling scans that the opponent then handles. Maximum two scans per side per turn regardless of the number of ships and you cannot use the same sensor twice in a turn. The player with lowest Initiative scan first, describing both scas to the target player before the target responds. This is so you don’t learn something from the first scan when planning the second scan. When both scans have been resolved it is the high Initiative players turn to do two scans and the low Initiative player to respond.

A scan consist of a type (Visual, IR, Radar, Neutrino or Mass), strength (sensor strength modified by scan size and ship damage), size (5 x 5 boxes, 3 x 3, boxes, 1 box, 3 x 3 squares or 1 square scans in inceasing strength but smaller area) and the center (box or square depending on).

Now it is the target’s turn to ask a number of questions, which questions depends on where the scan was placed. Below I’ll describe three consecutive scans on three turns by one side (player A) and the questions and results from player B. These examples are also available in the rulebook, on page 11.

Scan 1
A has his ship located in 1 and decides to do a 1 box Scan in box B4. His Sensor is +2 and the scan modifier for a 1 box scan is -1.
Player A ”I have a visual scan, strength +1, one box large, in box B4.”
Player B ”Does your Scan touch your ships Sunglare column?”
Player A ”Yes, my Scan touches my sunglare, dammit!”
Player B ”Is your scanning ship inside a gravity well?”
Player B ”No it does not scan from within gravity”
There could have been up to three more questions but none of them apply.
The scanner grudgingly admits that the Scan does touch his Sunglare column so the target reduce his Scan strength by -6 to an abysmal -5. If the target had ships or missiles inside the entire Scan he would hav added -5 to their Visual(Hull) and Visual(Thrust) signatures and if the sum came up 0+ he would have told the scanner the sum, given the position of the target(s) to him and the scanner would do a Sensor  task roll to see if ge got a Tracked result. The target player now also knows that the scanner’s ship is somwhere below the box.
I have colored the entire Scan 1 orange because of the Sunglare strength reduction, the Scan is still valid but very weak. Don’t stare into the sun.

Scan 2
Player A has moved his ship into position 2 and decide to do a huge 3×3 box scan centered around E1. The scan modifier for a 3×3 scan is -3 so his Scan strength is -1.
Player A ”I have a Visual Scan strength -1 three by three boxes in box E1.”
Player B ”Does your Scan touch your ships Sunglare column?”
Player A ”No it doesn’t. I have learned my lesson”
Player B ”Is your scanning ship inside a gravity well?”
Player A ”Eh, yes it is”
Player B ”OK, what blocked near and far sector touches your scan?”
Player A ”The northeast near and far sector”
Player B ”Thanks, are you scanning from the shadow column”
Player A ”No”
The northeast near and far sector is colored gray in the pictures. If player B had any ships or missiles inside the parts of the scan inside northeast near and far those targets would have been ignored. The near is simply the gravity sector and far extends from that forever. The Scan touches the Sun column but as player A wasn’t scanning from the Shadow column this had no effect.
I have colored the parts of the scan that should be ignored in red.

Scan 3
Player A has drifted into position 3 with the help of gravity. He decides to do a 3×3 box Scan in E4. He figures the Shadow column will protects him from Sunglare. The Scan strength is -1.
Player A ”Visual Scan strength -1 three by three boxes in E4.”
Player B ”Does your Scan touch your ships Sunglare column?”
Player A ”No”
Player B ”Is your scanning ship inside a gravity well?”
Player A ”No”
Player B ”Are you scanning from the shadow column”
Player A ”Yes”
Player B ”Your scan touches gravity, what blocked near sector does it touch?”
Player A ”Damned! The north near sector is blocked”
The Sun column as well as the near north sector will be ignored but most of the Scan is still valid as you can see. Had his scanning ship been 3 squares to the right none of the Scan would be blocked but he would suffer Sunglare.
I have colored the Sun column and north near sector of the Scan in red.

Scan procedure examples

As you can see, the procedure is quite simple: Scanner decides on a scan, tells type, strength, size and center to the target. The target then asks a bunch of questions and depending on the answers certain parts of the scan will be ignored.

Don’t stare into the sun you hippy you!


Posted in Intercept, Rules on October 3, 2015 by Mr Backman


The lunar eclipse which coincided with the moon being closest to earth was a rare thing indeed. It won’t happen again until 2035. Too bad it was overcast as usual here in Uppsala but it got me thinking about a scenario during an eclipse. Download the scenario Data cards and the eclipse map here, and the latest rules etc here.

A Mercenary cruiser without its onboard cutters, is tasked with prohibiting drug runners from Luna to land. The lunar cartel launches two ships, one Freetrader and one Fartrader, both unloaded to try to land on earth while the mercs job is making sure they don’t. The Broadsword class is pretty hard to damage by the traders but Surface, Power and Thrust sections can be damaged. If both tráders surviva landings that side wins a major victory, if only one trader lands the traders win a marginal victory. If none of the traders manage to land the mercenaries win.

Traders start two squares south in the lunar shadow column, the mercenary cruiser start two squares north in the earth the sun column (which is 3 squares wide), speed is 0 in both cases. Broadsword is side A and the traders side B. If you want you can play this as a three player scenario where Broadsword is A, Fartrader is B and Freetrader is C. Whoever lands first wins, if nobody lands the mercs win.


High Gs and very tough to damage but you’ll have to hinder two separate ships from landing.

  • 2.9 Gs. 2G every turn, 3G on turn 1, 2 and 3 of every four turns.
  • -2 on beam firing when thrusting due to underpower.
  • +0 Visual/IR, +2 Radar.


Low Gs but OK Visual/IR sensor and cold start missiles

  • 1.8 Gs, 1G every turn, 2G on turn 1, 2 and 3 of every four turns.
  • -2 on beam firing when thrusting due to underpower.
  • -1 Visual/IR, -3 Radar
  • This ship has 3G15 Coldstart missiles instead of the usual 5G15 used by the FarTrader


High Gs but easy to spot and shitty Visual/IR sensor

  • 2.5 Gs, 2G every turn, 3G on turn 1, and 3 of every four turns.
  • -2 on beam firing when thrusting due to underpower.
  • -3 Visual/IR, -3 Radar

This scenario will teach you how Sun column and Shadow column works so look that section up and read carefully. Also note that your landing must take aerobrake into account, don’t try to land with too high speed as this may cause your ship to burn and crash.

Update 3.4.1

Posted in Intercept on July 10, 2015 by Mr Backman

Image courtesy of mr Ian Stead

The new version is, as usual, available here.

Under power Thrust and Drift
Under power DMS are modifiers to beam fire when the power requirements for the ship and weapons are larger than what can be supplied by the power plant. Under power Thrust is for when the ship is thrusting and Under power Drift is for when the ship is drifting. Under power DMs are automatically calculated by the spreadsheets, power using Sensors are now included in the ships required power.

Aerobrakes etc
Aerobrakes and dock, ram & land now have their proper place in the sequence of play. It is now possible to do a aerobrake followed by a reverse thrust to zero speed, IF the Pilot task was VGood as the 180 degree turn after aerobrake costs 8 steps of turning (4 steps, x2 for using the Turning after thrusting required to maneuver after aerobrakes).
Sun blinding has been renamed Sunglare and it is now the Scan targets job to remind the scanner of that, in line with how Sun & Shadow column and planet LOS is also the burden of the Scan target.

Other stuff
Sun & Shadow column and planet LOS rules have been merged into one section and clarified.
Attack arcs are now overlapping so for example left and right arcs share a common centerline where both bear, this is known as ‘the money lane’ for top/bottom. Large scale optional rules have been updated with Repair and Power up rules.

Filled in DataCards
I have made some already filled in DataCards for some of the well known Traveller designs, ready for printng and use. They are contained within the Designs download.


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