High Guard to Traveller Fourth Edition (T4) Conversion


Rob Flammang, one of the members of the Traveller Mailing List, posted these rules back in February 1997. They provide guidance for conversion of Classic Traveller Book 5 (High Guard) starship designs to T4 format ships as designed by the QSDS rules in the main rulebook. The rules are posted here as an unmodified html file - it is hoped to format them sometime later to an Acrobat PDF. In the mean time, thanks to Rob's kind permission, here is the solution for everyone missing the simplicity of High Guard.

Well, I've been promising for a long time to post some rules for the conversion of High Guard USP's to T4 USP's. The advantages to using High Guard (and Book 2) to design starships are:

1) it's easier than any of the methods currently in print;
2) you can actually easily design ships that are compatable in price and capability with the ships listed in the T4 rulebook.

I've been lobbying for a HG-like ship design system for nearly a year now. If you ever plan to resurrect High Guard (or anything like it), Marc, feel free to use this system or any system based on or inspired by it. It's all yours.

These rules are not yet complete (two items have yet to be finished: meson screens and repulsers), but I figured I'd go ahead and post what I had. Please, please, please send me lots of advice and criticism.

Coming soon to a post near you: T4 USP's for:

Type A Free Trader
Type A2 Far Trader
Type R Subsidized Merchant
Type S Scout Courier
Type Y Yacht
The Patrol Cruiser
The Mercenary Cruiser
The Lab Ship
The Safari Ship
Ad Astra class Liners
Kinunir class Battle Cruisers
Unicorn class Close Escorts
The Gunned Gig
The Transport Pinnace
Lightning class Cruisers
Rampart class Fighters
The Armed Launch
The Fuel Shuttle
Zhodani Shiva class Patol Frigates
The Rock
The Pebble
Leviathan class Merchant Cruisers
 
Converting from High Guard USPs to the new USPs in Marc Miller's Traveller.
 
TONS
The T4 tonnage is the same as the HG tonnage. Take the Tonnage USP value directly from the HG USP.
For the hull type, use the following table to go from the HG configuration USP to the T4 USP:
 
HG USP T4 USP
1 Needle/AF
2 Wedge/AF
3 Cylinder/SL
4 Box/SL
5 Shere/SL
6 Dome/SL
7 Close Structure/No SL
8 Planetoid/No SL
9 Planetoid/No SL
 
VOLUME
 
Volume is equal to tonnage times 14. V = 14 * T.
 
COST IN MCR
 
Same for T4 as in HG.
 
CREW
 
Same for T4 as in HG.
 
PASSENGERS HIGH/MEDIUM
 
Same for T4 as in HG.
 
PASSENGERS LOW
 
Same for T4 as in HG.
 
CARGO
 
Should be listed in tons; same for T4 as in HG. If you list it in
cubic meters instead, then multiply the HG USP for cargo by 14 to get
the T4 USP.
 
CONTROLS
 
For starships, Mil Std/Bridge. For small craft, Mil Std or Mil
Std/Bridge if you include a small craft bridge. If the HG computer USP
is A, B, C, D, E, F, G, H or J, then add "/fib" to the T4 USP.
 
TECH LEVEL
 
Same for T4 as in HG.
 
SIZE RATING
 
Use the table below to convert from the HG USP size rating to the T4
USP:
 
HG size USP T4 size USP

0 7
1-9 8
A-J 9
K-Q 10
Q-X 11
Y 12
 
JUMP RATING
 
Same for T4 as in HG.
 
G RATING THRUSTER PLATES
 
Same for T4 as in HG.
 
POWER PLANT RATING
 
Same for T4 as in HG. To get the power plant rating in MW, multiply
the power-plant USP by the ship's tonnage, and multiply that by 2.5.
Power in MW = 2.5 * Tonnage * PP.
 
FIRE CONTROL RATING and SENSOR RATINGS
 
I suggest getting these from the HG "computer" USP using the following
table:
 
HGComp T4-fire-control T4-SensorUSP's (A P J)

0 0 0 0 0
1 1 2 2 2
2 2 4 4 4
3 3 6 6 6
4 4 8 8 8
5 5 10 10 10
6 6 12 12 12
7 7 14 14 14
8 8 16 16 16
9 9 18 18 18
A 1 2 2 4
B 2 4 4 8
C 3 6 6 12
D 4 8 8 16
E 5 10 10 20
F 6 12 12 24
G 7 14 14 28
H 8 16 16 32
J 9 18 18 36
R 1 2 4 2
S 2 4 8 4
 
ARMOUR 
I show below two versions of HG-to-T4 armor conversion. The first is
from the following official sources: HG to Striker, then Striker to
FFS. But the conversion from HG to Striker, while official, is also
very arbitrary. So I have substituted the arbitrary HG-Striker
conversion with my own arbitrary and easy HG-T4 direct conversion.
 
HG USP Official T4 conversion Easy T4 conversion
0 17 0
1 23 10
2 26 20
3 30 30
4 34 40
5 38 50
6 44 60
7 47 70
8 50 80
9 54 90
10 58 100
11 61 110
12 65 120
13 69 130
14 74 140
15 79 150
16 82 160
17 85 170
18 88 180
19 92 190
20 95 200
21 99 210
 
STRUCTURE
 
Get the T4 structure USP from the HG tonnage using the following
table:
 
HG tonnage T4 structure USP
0+ 0
3+ 1
7+ 2
13+ 3
20+ 4
27+ 5
33+ 6
42+ 7
50+ 8
67+ 9
83+ 10
125+ 11
167+ 12
208+ 13
250+ 14
292+ 15
333+ 16
417+ 17
500+ 18
583+ 19
667+ 20
750+ 21
833+ 22
1,000+ 23
1,167+ 24
1,333+ 25
1,500+ 26
1,667+ 27
1,833+ 28
2,167+ 29
2,500+ 30
2,833+ 31
3,167+ 32
3,500+ 33
3,833+ 34
4,500+ 35
5,167+ 36
5,833+ 37
6,500+ 38
7,167+ 39
7,833+ 40
9,167+ 41
10,500+ 42
11,833+ 43
13,167+ 44
14,500+ 45
15,833+ 46
18,500+ 47
21,167+ 48
23,833+ 49
26,500+ 50
29,167+ 51
31,833+ 52
37,167+ 53
42,500+ 54
47,833+ 55
53,167+ 56
58,500+ 57
63,833+ 58
74,500+ 59
85,167+ 60
95,833+ 61
106,500+ 62
117,167+ 63
127,833+ 64
149,167+ 65
170,500+ 66
191,833+ 67
213,167+ 68
234,500+ 69
255,833+ 70
298,500+ 71
341,167+ 72
383,833+ 73
426,500+ 74
469,167+ 75
511,833+ 76
597,167+ 77
682,500+ 78
767,833+ 79
853,167+ 80
938,500+ 81
 
LASER BATTERIES
 
Use the table below to convert from HG laser-battery USP's to T4
laser-battery USP's. Two T4 laser-battery USP's are given, one for
beam lasers and another for pulse lasers.
 
HG USP - Pulse Lasers - Beam Lasers

1 2-1-0-0 1-1-1-1
2 3-1-0-0 2-2-2-2
3 4-2-1-0 3-3-3-3
4 5-2-1-0 4-4-4-4
5 6-3-1-0 5-5-5-5
6 7-3-1-0 6-6-6-6
7 8-4-2-1 7-7-7-7
8 9=4=2=1 8-8-8-8
9 10-5-2-1 9-9-9-9
 
PLASMA and FUSION GUN BATTERIES
 
Use the table below to convert HG plasma or fusion gun batteries to T4
battery USP's:
 
HG USP T4 USP
1 3-0-0-0
2 4-0-0-0
3 5-0-0-0
4 6-0-0-0
5 7-0-0-0
6 8-0-0-0
7 9-0-0-0
8 10-0-0-0
9 11-0-0-0
 
MESON GUNS and PARTICLE ACCELERATORS
 
Use the table below to convert HG USP's to the T4 battery USP's for
meson guns and particle accelerators. These conversions were made by
using the relationship between the HG size USP's, which are linked to
weapon USPs, and the the T4 structure points.
 
HG USP Meson Gun Particle Accelerator

1 1-0-0-0 1-1-1-1
2 2-0-0-0 2-2-2-2
3 3-1-0-0 3-3-3-3
4 4-2-0-0 4-4-4-4
5 5-3-1-0 5-5-5-5
6 6-4-2-0 6-6-6-6
7 7-5-3-1 7-7-7-7
8 8-6-4-2 8-8-8-8
9 9-7-5-3 9-9-9-9
A 13-10-7-5 13-13-13-13
B 19-16-13-10 19-19-19-19
C 24-21-18-15 24-24-24-24
D 25-22-19-16 25-25-25-25
E 26-23-20-17 26-26-26-26
F 28-25-22-19 28-28-28-28
G 29-26-23-20 29-29-29-29
H 29-27-24-21 29-29-29-29
J 31-28-25-22 31-31-31-31
K 32-29-26-23 32-32-32-32
L 38-35-32-29 38-38-38-38
M 42-39-36-33 42-42-42-42
N 44-41-38-35 44-44-44-44
P 46-43-40-37 46-46-46-46
Q 50-47-44-41 50-50-50-50
R 52-49-46-43 52-52-52-52
S 58-55-52-49 58-58-58-58
T 62-59-56-53 62-62-62-62
 
SANDCASTER BATTERIES
 
Use the table below to convert from the HG USP to the T4 USP. The T4
USP is given for 3 tech levels.
 
HG USP TL-7 TL-8 TL-10
0 0 0 0
1 1 - -
2 3 1 -
3 6 3 1
4 8 6 3
5 10 8 6
6 20 10 8
7 30 20 10
8 - 30 20
9 - - 30
 
MISSILE BATTERIES
 
Use the table below to get the number of missiles that can be
controlled in flight by a battery at any one time from the HG USP
factor. Two columns are given for 2 different tech levels.
 
HG USP TL-7 TL-13
0 0 0
1 1 -
2 3 1
3 6 3
4 12 6
5 18 12
6 30 18
7 60 30
8 120 60
9 180 120
 
FORCE FIELDS
 
The flicker rate of the black globe is equal to the HG force-field USP
time 10%.
 
NUCLEAR DAMPERS
 
Set the T4 USD equal to the HG USP plus 1.
 
And now for the two remaining problems:
 
REPULSOR BATTERIES
 
I do not know how repulsors are handled in T4. Despite a cryptic
reference on page 72 of "Starships", there is no table of them that I
can find.
 
MESON SCREENS
 
I do not know how meson screens are handled in T4. Despite a cryptic
reference on page 75 of "Starships", there is no USP value in the
table on p100 that I can find.
 
(c)1997,1999, 2005 Rob Flammang