The Traveller, 2300AD, Twilight: 2000 and Dark Conspiracy games in all forms are owned by Mongoose Publishing. Copyright 1977 - Mongoose Publishing. Traveller is a registered trademark of Mongoose Publishing. Mongoose Publishing permits web sites and fanzines for this game, provided it contains this notice, that Mongoose Publishing is notified, and subject to a withdrawal of permission on 90 days notice. The contents of this site are for personal, non-commercial use only. Any use of Mongoose Publishing's copyrighted material or trademarks anywhere on this web site and its files should not be viewed as a challenge to those copyrights or trademarks. In addition, any program/articles/file on this site cannot be republished or distributed without the consent of the author who contributed it.
Your email address is used as your unique player identifier — it is how your account, your ship designs, and your battle records are tied to you.
We may use it to contact you about bug reports you submit, and possibly in the future as part of a communication tool for a Trillion Credit Squadron update.
Your email address is never shared with third parties outside this website.
What is High Guard Rules?
High Guard Rules brings Classic Traveller's Book 5: High Guard starship construction and combat rules to the web.
Ship Designer walks you through building a warship from the keel up — hull, jump and maneuver drives, power plant, computer, weapons, and screens — following the Book 5 construction sequence, with every calculation (tonnage, energy points, agility, cost) handled for you automatically.
Combat Arena lets you pit your designed ships against another player, or fly solo against an AI opponent — resolving the full Book 5 ship-to-ship combat sequence round by round: Battle Formation, Initiative, Range, Pre-Combat Decisions (break-off, emergency agility, surrender), Combat, Damage, Breakthrough Combat, Pursuit, and a Terminal step for boarding, repair, and crew transfer.
Ship Library keeps your saved designs on hand, and Meeting Room is where you find another player and start a battle.
Whether you're building a fleet, sparring with the AI, or working through a firefight against another captain, this site handles the math so you can focus on the tactics.
Fair Use Policy
Email Address Policy
Win/Loss Record
Bug Report
Ship Details
Universal Ship Profile — USP Key
Email not verified. Check your inbox for a verification link.
Resend email
Select a design from the list to view its profile.
Online Players
No other players online.
Click a player's name to open a channel.
Contact
Incoming contact request from
Accept
Decline
IDENTITY — Private Design
Hull
?
Tonnage Code sets the USP digit for your hull's size band — e.g. code '1' covers 100–199 tons,
code 'A' covers 1,000–1,999 tons.
Actual Tonnage is the precise value used for every calculation (cost, EP, crew, etc.); changing the code snaps it to that band's floor, but you
can then dial it anywhere within the band without changing the code.
Configuration sets the hull cost multiplier:
1 Needle/Wedge ×1.20
2 Cone ×1.10
3 Cylinder ×1.00
4 Close Structure ×0.60
5 Sphere ×0.70
6 Flattened Sphere ×0.80
7 Dispersed ×0.50.
8 Planetoid and 9 Buffered Planetoid skip the multiplier entirely and instead cost MCr 0.0011/ton for the interior
Config 8 & 9 have automatic armour of 3 and 6 respectively at no extra tonnage
or cost. Config 7 (Dispersed) can carry no armour at all. Configs 7, 8, and 9 are all
non-streamlined, so none of them can mount fuel scoops. Config 7 also removes the normal
launch/recovery rate limit in combat entirely — a Dispersed hull can launch and recover every
carried craft in a single turn, regardless of launch tubes or the tonnage-based default rate.
Configs 8 and 9 (Planetoid, Buffered Planetoid) cannot be used for small craft.
Drives
*
PP number must equal or exceed the higher of Jump or Maneuver rating.
Fuel
Small craft: scoops built-in for streamlined/partial hulls (configs 1–6). No purification plant required.
Bridge & Electronics
?
Auxiliary Bridges soak up Bridge Destroyed critical hits before they land: each aux bridge
absorbs one hit outright — command transfers to it, no penalty at all — consumed one at a
time. Only once every aux bridge is gone does a Bridge Destroyed hit actually land: it halves
your current computer factor (rounded down) and zeroes both the maneuver and jump drives for
the rest of the battle.
Computer model number sets the largest jump your drive can be controlled for — Model/1
controls Jump-1, Model/5 controls Jump-5; models above 6 add no further jump capability.
'fib' adds a fibre-optic backup that resists radiation damage;
'bis' is an improved design that also
controls one jump number higher than its plain counterpart — Model/1bis controls Jump-2
despite the /1. Both cost more than the plain model.
Hull tonnage sets a minimum model too —
a 10,000-ton hull (code K) needs at least Model/4 — and the dropdown hides any model too
small for your current hull.
Small craft can only mount plain models, never fib or bis.
No bridge — operates as Model/X-1 in combat
Small craft requires a bridge, computer, or both. Bridge provides life support and couches for 2 persons.
Armour & Screens
?
Armour Added can't exceed your ship's tech level, and its tonnage/cost per point both scale with TL.
Config 7 (Dispersed) can't be armoured at all — Armour Added stays locked at 0.
Configs 8/9 (Planetoid, Buffered Planetoid) get automatic inherent armour of 3/6 for free, shown in Inherent
Armour; Armour Added stacks on top of that.
The three screens defend against different things — Nuclear Damper may neutralize incoming nuclear
missile warheads;
Meson Screen (a damper variant) may block meson gun fire specifically;
Force Field
(Black Globe) absorbs ALL incoming energy of any kind and redirects it into your ship's capacitors
instead of taking damage.
All three need power (EP) and are TL-gated — the dropdown hides codes
your ship's TL can't build yet.
A Force Field needs somewhere to put the energy it absorbs: your jump drive already carries
built-in capacitors (0.5% of hull mass per jump number), and Additional Capacitors (below) buy
more at 36 EP storage and MCr 4.0 per ton. In combat, a black globe can run at partial power
(Flicker) for partial protection while still allowing you to fire, or Fully On for total
protection at the cost of not firing or maneuvering that turn.
36 EP storage / ton · MCr 4.0 / ton
Weapon Allocation
?
Hard Points measures your available turret mounts: 1 per 100 tons of hull, computed off
tonnage remaining after spinal mount and bay weapon tonnage are subtracted — not raw hull
tonnage.
Bays are separate: 1 bay allowed per 1,000 tons of hull (floored), and ships under
1,000 tons can't mount bay weapons at all.
Hard Points and Bays draw from separate pools and
don't trade off against each other directly — only indirectly, since spinal/bay tonnage eats
into the pool Hard Points are computed from.
Spinal Mount
Bay Weapons (one entry per weapon type)
Weapon & Bay Size (Code at current TL)
Bays
Turret Weapons (batteries per weapon)
Weapon (USP factor at current TL)
Batteries
Carried Craft
?
Small craft/fighters use a 1.3× hangar-tonnage multiplier if the carrying ship is over
1,000 tons (1.0× otherwise); large craft always use 1.1×, regardless of hull size.
Leaving a Small Craft row's USP field blank makes it a vehicle instead of a craft: zero
cost, no pilot/gunner/maintenance crew requirement, and its raw tonnage with no hangar
multiplier. Fill in a USP and it's treated as a real craft.
The "Is Ftr" checkbox marks a row as fighters. Fighter counts must always be a multiple
of 10 — one squadron is 10 fighters — whether they're an ordinary Small Craft row or
stored in an empty bay below.
Bay Weapons has its own way to carry craft: pick "Empty Bay" as that row's type and a
Carried Craft sub-form appears under it. Capacity there is only half the bay's tonnage
(bay count × bay size ÷ 2), not the full bay tonnage — budget accordingly.
Continue keeps playing now, protected if either of you disconnects later.
Exit saves it and returns both players to the Meeting Room right away.
Allocate Batteries
Allocate Active Defenses
?How do these controls work?
Each block is one incoming hit; beneath it are the defense types your ship can use against
it (sandcaster, repulsor, or beam laser/energy — only the types that apply to that weapon and
that you still have batteries for are shown). Use +1/+5 to spend batteries of that type
against that hit and -1/-5 to take them back. The legend above the rows shows how many
batteries of each type you have left to allocate — click a legend badge to toggle it on/off
(dimmed = off); only the types left on are affected by the Water-fill buttons.
Water-fill Defenses Dn and Up both spread your remaining batteries of each
selected type as evenly as possible across every hit that type can defend against,
overwriting only that type's allocations. They differ only in where the leftover goes when
the pool doesn't divide evenly: Dn gives the spare batteries to the hits at the top
of the list, Up to those at the bottom. Since hits are ordered by weapon type and
then factor, Up is the one that favours the heaviest incoming fire. Reset zeros out every hit's allocation for
all types, regardless of the legend selection. Resolve Defenses submits your
allocation and continues; Cancel clears it and backs out without submitting.
If this dialog gets closed accidentally before you resolve it, the group card behind it
shows a Show Form button to reopen it without losing your allocation.
If your ship's crew factor has dropped from its starting level (Crew-n), it has no active
defense at all — sand, repulsors, and defensive beam fire are all batteries being fired, and
Crew-n bars firing anything, active defense included. Incoming hits still resolve against
whatever passive defenses (armor, screens) it has left.
