Classic Traveller - Space Combat

TOC

• CT Review Table of Contents

• Introduction

• Generating characters

• Classic Traveller - Combat

• More IronMongery

• Travel

• Starship Economics and Design

• Computers

• Space Combat

• Space Combat - plugging rules

Space Combat

Encounters in space can be routine, or they can be extraordinary. In some circumstances, battles may result. Starship battles may be resolved by spaceship combat with miniatures in accordance with the following rules. These rules serve well in nearly all situations, from simple encounters where a free trader attempts to outrun a pirate or revenue cutter, to the complex engagements between starship squadrons of rival systems or empires.

A few notes before I go through this section.

I loved this as a kid. Drew out a number of planetary templates, got paper and pencil and rulers, and marveled at how simple the movement system was. It also turns out this wasn’t Marc’s first or only rodeo in this style of space combat. At vastly different scales - and Triplanetary laughs at your concepts of consistent scale - the same basic movement system was laid out in Triplanetary and Mayday. For that matter, the combat rules in Mayday are essentially the same as in Traveller as well, because it’s basically a hex-and-chit boardgame version of Traveller. CT Book combat operates with the following assumptions for scaling:

• 1000 second turns (Mayday is six times that at 100 minutes).

• 1:100000000 scale (1 mm = 100 km) - Mayday has 1 hex = 1 light second (three meters in CT tabletop combat)

• The above numbers are not chosen arbitrarily. In CT 1G of thrust results in a change vector of 100 mm, where in Mayday (and Triplanetary) 1G of thrust changes your vector by 1 hex.

Some basic info on maneuver capabilities, available programs, and weapons and mountings need to be noted down for each ship with some notes on what to ignore or note down for non-starships or small craft.

The basic turn sequence is actually on page 74. The “Intruder” takes his full turn, then the native player does. Each, on their turn:

1. Moves (ordinance launched on previous turns moves at this time too)

2. Fires lasers (and nothing else).

3. The other side then gets to return fire if they have the appropriate program in active memory or can fit it in active memory from standby storage. Or they can shoot at incoming missiles.

4. Launch ordinance - missiles and sandcasters. This is also when missiles explode if they contacted an enemy ship.

5. Reprogramming the computer - loading and unloading software into and out of active and standby storage. This is the only phase you can load a program from cold storage/discs/cartridges/cards.

After both sides have moved, planets/etc. move as needed, plus whatever other miscellaneous activity is needed, rinse, lather, repeat.

Movement

This takes far longer to explain than show. Most of a page is spent elaborating on this as well as limitations, etc. - it manages to be simple to use while providing a decent approximation of realistic rather than star-wars style movement. This is compressed to two dimensions, and doesn’t care about relative ship orientations over the time scales involved for damage or available weapons, so Attack Vector:Tactical, or Squadron Strike, this is not.

Let’s say your ship is moving with a vector of 400mm (relative). You thrust at 90 degrees at 1 G, so add a 100 MM arrow 100 mm long to the head of your original vector, and draw a new line from the start of your original vector, and the end of the new one.

Gravity is accounted for by noting if the midpoint of the vector passes through the field of a large body or planet, and added to the sum of the current vectors.

Firing Lasers

All lasers in a turret need to fire on the same target - and a ship cannot engage multiple targets unless the appropriate program is loaded. The target is an 8+. Obvious modifiers exist for range, use of evasive or predictive software, and so on.

Assuming the attack hits, it takes effect immediately before the next (return fire) phase and you roll for damage location - allowing for hits to the power plant, maneuver drive, jump drive, hull, fuel tankage, computer, turrets, or even critical hits to completely incapacitate systems rather than degrade them.

Incidentally, yes, this means laser return fire happens after damage is received and allocated for incoming laser fire.

Also - fire is allocated before rolling to hit or for damage - you can shift fire if a target is disabled or destroyed, but at a severe penalty.

Ordinance

This segment is incomplete. Yes, you can launch sand and missiles with the appropriate software loaded, and none of them move until your next movement phase, but how send behaves or moves after that, or how missiles move and how fast they accelerate is completely overlooked.

Rules for impact/detonation are handled, as well as reloads, capacity, etc.

So what do we do? The two options I’ve found were to look at Mayday, despite it’s different scale, and SS3 - Missiles (which Mayday explicitly grants primacy to).

Well - sand. Mayday states that it stays around the ship as a defensive screen, and that maneuvering takes you out of it’s protection and disperses it: it’s a sand cloud without thrusters.

From page 8 of Mayday:

Ships equipped with sandcasters may launch clouds of obscuring crystals (sand) which interfere with laser fire and small weapons such as missiles.

Sand may be launched in the ordnance launch phase, provided that the missiles are not launched from the ship in that phase. The launch program must be running in the computer for the sand to be hunched.

Mark the present position counter of the launching ship with a blank white counter. For as long as the ship does not change course, the counter remains in place, indicating that a cloud of sand surrounds the ship.

Effects: Sand hinders laser fire. lncoming laser fire is subject to a DM of -3; outgoing laser fire is subject to a DM of -1.

Sand affects incoming missiles slightly. Missiles receive a DM of -1 on the attack table if the target is in a sand cloud.

Dispersal: A sand cloud remains; in place for as long as the ship does not change course, It dissipates when the ship does alter course.

A ship has a store of sand equal to its tonnage (a 100 ton ship has 100 shots of sand normally 1, which is effectivety unlimited in the course of a Mayday scenario. Sand can only protect the launching ship; it cannot protect another ship, a missile, or a small craft.

Nothing here contradicts what’s in CT (-3 for every 25mm which would constitute one sand cloud). If anything, there are penalties for the protected ship as well.

And missiles?

Mayday operates at a different time scale and should be treated as a different game. One aspect this markedly changes things is detection and tracking ranges, another is that missiles are still rated on the same number of G’s of thrust and how many turns, despite the different scales. And missiles receives its own entire supplement. That said, I’ll summarize the standard ship’s missile from page 4 of SS-3:

For example, the standard missile in Traveller is a 5G6 continuous burn (36 kg, Cr3,600, TL 8), mass sensing (1 kg, Cr1,000, TL 10), proximity detonator (1 kg, Cr500, TL 6), high explosive (10 kg, Cr500, TL 6) warhead missile (all produced at their standard tech level), costing Cr5.600 and massing 48 kg. This price does not take into account tech level effects. At TL 9, this missile costs Cr5,540; at TL 12, it costs Cr4,480.

To break that down, this Cr5,540 missile (cheaper at higher TLs):

• 5G’s of thrust (500mm vector change)

• For 6 turns of continuous burn

  • meaning it accelerates in the same direction at full 5G thrust for 6 turns

  • and continuous burn missiles do no major course changes - they’re basically highly advanced rockets with terminal guidance. Limited and discretionary burn missiles require more fuel reserves but also have the ability to change course.

• It uses a mass-sensing detector (rather than infrared, neutrino/power plant, or radio-guided/radiation-seeking)

• The proximity detonator goes off in proximity to the target not requiring contact - and can be countered by ECM

• It has a high explosive warhead rather than some form of shaped charge or nuclear warhead. This means that it does two hits on intercept. This is actually in contravention of the missile detonation rules on TTB p. 76, which allow for 1-6 hits based on supposed distance at time of detonation.

A missile intercepts a target if it passes within 25mm for terminal guidance.

Detection

A couple quick paragraphs lay out the differences in detection and tracking ranges of military grade sensors and civilian - and leaves open the question of how to obtain such if one wanted to spend extra on a military grade suite. Ships construction rules don’t seem to have a different space or tonnage requirement. That said, that little scout courier has scout-grade sensors.

Damage

A quick explanation of what happens when each major system is damaged. The short version is that capabilities are degraded unless it’s a critical hit. It’s also interesting that power plant hits are nastier because if a power plant damage degrades it below the current maneuver or jump drive rating, that drive is now unusable. This rule can be read that if a maneuver drive is damaged in turn, that it can come back online, but doesn’t have to be, and I’m not sure I’d allow that.

Special Situations

We cover a few things like atmospheric braking and explosive decompression, as well as abandon ship procedures, damage control, and repairs. This is one place where a PC with a high level of skill can really shine. Subject to availability of repair parts, of course.

Encounters

A quick explanation of the random encounters table. The type and number of ships, and the likelihood of the ship being a pirate, are affected be the general starport class.

Templates

Since this is a game involving space travel, and the nature of the jump drive dictates that most encounters will happen within 100 planetary diameters, you of course need to have planets on the board. This section describes how to draw out a template for use in combat.

There’s also a handy chart with typical distances for standard planet sizes on page 79. Looking at Jupiter as an example - the gravitic effects of that system can have far-reaching consequences well in excess of the size of a large table, and ships without some built-up velocity or high thrust will have difficulty escaping from the nearest bands.

Conclusion

Overall, the system is evocative, and leaves room, even without High Guard rules, for incorporation of stealth systems to mask IR signatures (temproarily), etc., but the missing missile movement rules requires us to go outside of the core books for what should have been a basic inclusion (thrust a x G, for y turns, either on a constant vector or with some course correction allowed) as well as a line or two on how sand behaved. At least once you look at SS3, you have an explicitly overriding rule that fills in these gaps, even if it also somewhat nerfs the standard missiles to a steady two hits and rather limited effective range without course correction options (and costs).

For larger venues like the system around a gas giant, it may be wise to rescale to smaller values like half of the presented scale, but this is easily workable.

While you’re at it:

If you like good books, the guys at Pilum Press have a discord server. Drop in, and if you haven’t yet, pick up a copy of everything they have at their website.

If you’re more into games, check out the Arbiter of Worlds channel, and the Autarch Discord server as well. There you will find discussions on ACKs, Ascendant, and a number of other non-Autarch RPGs and games like Traveller and D&D.