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Conversion rules

Kentares

SOC-11
Sorry if this has been mentioned before...

T20 will have conversion rules for the other Traveller systems (MT, TNE, etc...) ?
 
I have an idea of how to convert the Ability scores. In Classic Traveller the Initial values range from 2 to 12. Here is the procedure: Add 3 to each ability score and now subtract 10. These resulting numbers are now the Ability Score modifiers for the D20 Ability Scores. Check on page 20 of the Traveller Handbook and refer to the table on Ability Score Modifiers. The lowest possible modifier is -5 which corresponds to D20 Abilities 0 and 1. (You roll a 2 sided dice to decide which.) Continuing this progression: -4 corresponds to 2-3, -3 becomes 4-5, etc. A Traveller 12 becomes 5 which equals 20-21.

Strength becomes Strength
Dexterity becomes Dexterity
Endurance becomes Constitution
Intelligence becomes Intelligence
Roll 3d6 or 4d6 for Wisdom
Roll 3d6 or 4d6 for Charisma
Education becomes Education
Social Standing becomes Social Standing
 
Tom

that looks like a good idea but instead of adding and subtracting why not just subtract 7. It will get you to the same number
 
Well I'll throw my cr.02 in...

The only official basis of comparison seems to be the titled noble ranks (p 21 Social Standing). A table cross referencing CT and T20 would begin...


CT.....Title.....T20

15.....Duke......24
14.....Count.....22
13.....Marquis...20
12.....Baron.....18
11.....Knight....16


...continuing the progression didn't quite work so I flattened the range at the average point...

CT.....class.....T20

10.....rich.......14
09.....upper......12
08.....up. mid....11
07.....middle.....10
06.....lo. mid....09
05.....lower......08
04.....poor.......06


Anyway that's my take. Naturally you use the same conversion for all the ability scores and as pointed out CT Endurance is Constitution in T20. I think Agility was used in one version and that would of course be Dexterity in T20.

Of course the real trick is trying to convert all the skills. I did it for one TNE character to T20. It was basically generating a T20 character from start with an eye to ending up with the same relative abilities over the same number of terms. It did work out, in the end, but some of the order of acquisition had to be rearranged which changed the characters backstory some. I don't think there will be any hard and fast way to do skill conversions.
 
Looking at Dan's social standing table, it looks like multiplying CT stats by 1.5 (or dividing T20 stats by 1.5) would be a quick & easy conversion method. Of course that's no real surprise considering you roll 2D6 for CT stats and 3D6 for T20 stats.
 
I worked out my conversion rule when I played Alternity. In Alternity the Ability scores range from 4 to 14 for humans. In Traveller the range from 2 to 12. It is the same spread. the conversion rule from Alternity to D20 is simple, you just subtract 10 from the Ability score and it becomes the Ability score modifier in a D20 game The Wizards of the Coast probably adopted many of D20's game mechanics from their experiences with the Alternity Game. Traveller is not too different from Alternity. I could probably take the StarDrive Alternity setting and convert it to Traveller quite easily. To make Traveller stats Alternity-like you add 2 to them, then subtract 10 and you have the D20 Ability score modifiers and working backwards from their you can deduce the d20 scores. The main problem with simply mutiplying Traveller scores by 1.5 is that you don't get the full range of d20 scores. I'll show you what I mean: 2 becomes 3; 3 becomes 4.5 which rounds off to 5 etc. so the Traveller scores 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 become 3, 5, 6, 8, 9, 11, 12, 14, 15, 17, 18 respectively. Using the x 1.5 conversion rule you'll never get a character with an ability score of 4, 7, 10, 13, or 16. Everyone would then be able to tell that this was a converted character because it would lack those ability scores. My method recreates the full range of d20 scores. I have a choice in this instance. If I add 2 and then subtract by 10, I'll get certain ability score modifiers that don't exist in the D20 game. A Traveller score of 2 will produce an ability score modifier of -6. There is no such d20 ability score that will produce such a modifier. D20 ability scores can't be negative. You could always knock that ability score up to 1 however and improve the character through the conversion process. Another problem with this method is that it will tend to produce D20 characters whose average score is 9 or 8 because the average score rolled in Traveller is 7. I think that an average score should have no modifiers + or - so I add 3 and subtract 10. this produces a D20 character whose ability scores range from 0 to 21. This is not too bad since Traveller D20 characters often start above 1st level and level advancement in D20 offers opportunities to improve one's ability scores above 18 anyway.
 
The main problem with simply mutiplying Traveller scores by 1.5 is that you don't get the full range of d20 scores.... so the Traveller scores 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 become 3, 5, 6, 8, 9, 11, 12, 14, 15, 17, 18 respectively.
Considering your system never results in even numbers (why choose 16 when 17 would be equally valid and gets you closer to the next breakpoint), that's a rather strange complaint. Plus, the 1.5x method translates the 1-F range into 3-23, which looks a bit better than your proposed 0-27.
 
Here is my 2cred's view and how I am converting stats for my T4 campaign.

T4 Stats ---------T20 Stats

15 ---------------> 20
14 ---------------> 19
13 ---------------> 18
12 ---------------> 16-17
11 ---------------> 14-15
10 ---------------> 13
9 ----------------> 12
8 ----------------> 11
7 ----------------> 10
6 ----------------> 8-9
5 ----------------> 6-7
4 ----------------> 4-5
2-3---------------> 3

On the stats that convert to for example 16-17 either take a gm option or leave to chance (123=16 456=17).

V4 T20
Str --> Str
Dex --> Dex
End --> Con
Int --> Int
Edu --> Edu
Soc --> Soc
Chr --> Chr
X --> Wis

For wisdom I have been letting the player choose to
take the average of Int and Edu +1d3 or roll the stat with 4d6.

This seems to work ok for the stats.
 
Originally posted by Tom Kalbfus:
I worked out my conversion rule when I played Alternity. In Alternity the Ability scores range from 4 to 14 for humans. In Traveller the range from 2 to 12. It is the same spread.
That's true if Alternity rolls its 4-14 as 2d6+2, which seems the most likely but I've never looked at it.

Originally posted by Tom Kalbfus:
The main problem with simply mutiplying Traveller scores by 1.5 is that you don't get the full range of d20 scores. I'll show you what I mean: 2 becomes 3; 3 becomes 4.5 which rounds off to 5 etc. so the Traveller scores 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 become 3, 5, 6, 8, 9, 11, 12, 14, 15, 17, 18 respectively. Using the x 1.5 conversion rule you'll never get a character with an ability score of 4, 7, 10, 13, or 16. Everyone would then be able to tell that this was a converted character because it would lack those ability scores.
And that is bad how? The main thing with this conversion is that it maintains and produces the CT to T20 maximum initial ability score limit of 12 and 18 respectively. And it does in fact produce the full D20 range, though not every unit in that range I agree. That I guess is what you meant.

Originally posted by Tom Kalbfus:
My method recreates the full range of d20 scores. I have a choice in this instance. If I add 2 and then subtract by 10, I'll get certain ability score modifiers that don't exist in the D20 game. A Traveller score of 2 will produce an ability score modifier of -6. There is no such d20 ability score that will produce such a modifier. D20 ability scores can't be negative. You could always knock that ability score up to 1 however and improve the character through the conversion process. Another problem with this method is that it will tend to produce D20 characters whose average score is 9 or 8 because the average score rolled in Traveller is 7. I think that an average score should have no modifiers + or - so I add 3 and subtract 10. this produces a D20 character whose ability scores range from 0 to 21. This is not too bad since Traveller D20 characters often start above 1st level and level advancement in D20 offers opportunities to improve one's ability scores above 18 anyway.
Which I still see as a flaw in your conversion. Your system translates the CT 2-12 range to a D20 1-20 range. The problem is the CT 2-12 is the starting score range, which should translate to a D20 3-18 range. CT allows prior history to adjust this to a 1-15 range, just as T20 allows for adjustments through levels and injury, though with no upper limit.
 
Considering your system never results in even numbers (why choose 16 when 17 would be equally valid and gets you closer to the next breakpoint), that's a rather strange complaint. Plus, the 1.5x method translates the 1-F range into 3-23, which looks a bit better than your proposed 0-27.

I forgot to mention that you must add indormation in the Conversion process namely a 1d2 roll to determine whether its 0 to 1, 2 or 3, 4 or 5, 6 or 7, 8 or 9 etc.

Here is my 2cred's view and how I am converting stats for my T4 campaign.

T4 Stats ---------T20 Stats

15 ---------------> 20
14 ---------------> 19
13 ---------------> 18
12 ---------------> 16-17
11 ---------------> 14-15
10 ---------------> 13
9 ----------------> 12
8 ----------------> 11
7 ----------------> 10
6 ----------------> 8-9
5 ----------------> 6-7
4 ----------------> 4-5
2-3---------------> 3
Conversion is somewhat uneven that way. the most important thing ability scores do is provide Ability Score Modifiers in D20. In Traveller the Ability Scores are the modifiers so why not convert Traveller Ability scores into D20 Ability score modifiers? The D20 Ability scores can be derived fron those. (Which are a pair of ability scores which produce the same modifier, to determine which of the two it is roll a 1d2 or flip a coin.)

Which I still see as a flaw in your conversion. Your system translates the CT 2-12 range to a D20 1-20 range. The problem is the CT 2-12 is the starting score range, which should translate to a D20 3-18 range. CT allows prior history to adjust this to a 1-15 range, just as T20 allows for adjustments through levels and injury, though with no upper limit.
The 0 to 21 range could reflect the following:
A person with a str of 0 would be paralized, an Int of 0 indicates brain dead. I would default to 1, which means the character has animal intelligence or is severly retarted. Such characters are hopeless anyway so roll again. It's conceivable that Traveller characters could be genetically engineered to have ability scores above 18, this might be a relatively common occurance in the Traveller universe. Humaniti might also have evolved somewhat from the time they were swinging swords.
 
Originally posted by Tom Kalbfus:
The 0 to 21 range could reflect the following:
A person with a str of 0 would be paralized, an Int of 0 indicates brain dead. I would default to 1, which means the character has animal intelligence or is severly retarted. Such characters are hopeless anyway so roll again. It's conceivable that Traveller characters could be genetically engineered to have ability scores above 18, this might be a relatively common occurance in the Traveller universe. Humaniti might also have evolved somewhat from the time they were swinging swords.
Valid enough, I'm just against a conversion system where someone who rolled the best possible in CT of a 12 might bring that character into a T20 game (where someone else had rolled their character using T20 and has the best possible score of 18) and have a better score than if they had rolled it in T20. The player bringing the converted character will have with your system a 20 or 21 against the native system player's 18. The CT ability bonuses will I think widen this discrepency even more versus the same improvements of the T20 character. If you don't see the flaw here we'll have to agree to disagree. No harm no foul. Any game using converted characters is going to be more or less non-OT anyway.
 
There are trade offs in each one. Perhaps a better idea would be to add 2 and subtract 10. Any result that ends up below a D20 3 becomes a 3. That way you'd have a range of 3 to 18 instead og 0 to 21.
Alternatively you could multiply by 1.5. I thought of another way. You could multiply the interval between each traveler ability and the next whole number by 1.5 Here's how this method works: Say your Traveller Ability score is 2. There is a percentile range between 2 and 3 of 100 basis points going from 2.00 to 2.99. Multiply 2.00 by 1.5 gives you 3.00. Multiply 3.00 by 1.5 gets you 4.50. There are 150 basis points between 3.00 and 4.50. You therefore have 67% chance or 2 out of 3 chance of getting 3 as your d20 score and a 1 out of three chance of getting a d20 ability score of 4. Just roll a 1d3 (1d6/2) to find out which. The resulting progression is thus:
2 becomes 3 on (1d3) 2- or 4 on (1d3) 3
3 becomes 4 on (1d3) 1 or 5 on (1d3) 2+
4 becomes 6 on (1d3) 2- or 7 on (1d3) 3
5 becomes 7 on (1d3) 1 or 8 on (1d3) 2+
6 becomes 9 on (1d3) 2- or 10 on (1d3) 3
7 becomes 10 on (1d3) 1 or 11 on (1d3) 2+
8 becomes 12 on (1d3) 2- or 13 on (1d3) 3
9 becomes 13 on (1d3) 1 or 14 on (1d3) 2+
10 becomes 15 on (1d3) 2- or 16 on (1d3) 3
11 becomes 16 on (1d3) 1 or 17 on (1d3)2+
12 becomes 18
We'll disallow a result of 19 for beginner human characters to make it fair. Animals and NPCs however are fair game for continuing this progression.
 
I like your current progression much better then mine.

The 7 becomes the average 10/11 with zero mod. Thats what I was shooting for in my original table. It did penalize having an 8. Yours does not and works much better.

T4 Stats ---------T20 Stats

15 ---------------> 20
14 ---------------> 19
13 ---------------> 18
12 ---------------> 16-17
11 ---------------> 14-15
10 ---------------> 13
9 ----------------> 12
8 ----------------> 11
7 ----------------> 10
6 ----------------> 8-9
5 ----------------> 6-7
4 ----------------> 4-5
2-3---------------> 3

Thanks!!!
Mathamatics Challenged Hendel ;)
 
Glad you like it. Any of those methods will produce some kind of ability conversion. The next big challenge is to find character levels for converted Traveller characters. For example how do you convert this:

Scout 668675 Age 38 5 terms Cr121,400
Pilot-1, Rifle-1, Navigation-2, Medic-1, Air/Raft-2, Gunnery-1 Ship

into a T20 character with levels in the Scout class?
I look in by Traveller T20 Handbook and find that the scout class gets a +1 base attack bonus at level 2 which would cover for the Rifle-1 and Gunnery-1. On the other hand perhaps the fact that he served 5 terms indicates that he is at level 5? Also a Rifle-1 in Traveller could represent a greater bonus that a mere +1 in T20 since the old Traveller game rolls 2d6s instead of d20s for hit determination. A Rifle-1 is probably closer to a base attack bonus of +2 which would put the character at 3rd level.
 
I sir, Have served Five terms in the IISS, and have reached 9th level by way of my prior history... I am also a "split Class" (I served three terms as a Noble in my early life)

Its all what you get out of prior history... Therein lies the conversion...
 
Scout 668675 Age 38 5 terms Cr121,400
Pilot-1, Rifle-1, Navigation-2, Medic-1, Air/Raft-2, Gunnery-1 Ship

Lets try this:
Str 6 --if 1d6 = 4- then 9 else 10 --> Str 9
Dex 6 --if 1d6 = 4- then 9 else 10 --> Dex 9
End 8 --if 1d6 = 4- then 12 else 13 --> Con 13
Int 6 --if 1d6 = 4- then 9 else 10 --> Int 9
Wis 4d6 (best 3 rolls) --> Wis 7
Cha 4d6 (best 3 rolls) --> Cha 11
Edu 7 --if 1d6 = 2- then 10 else 11 --> Edu 10
Soc 5 --if 1d6 = 2- then 7 else 8--> Soc 7

T20
Scout 99D97BA7 Age 38 5 terms Cr121,400
Pilot-1, Rifle-1, Navigation-2, Medic-1, Air/Raft-2, Gunnery-1 Ship

5 Terms of Scout 5 x 4,000 xp + Training 3,000 xp + Routine 3,000 xp + Routine 0 xp, + Mission 3,000 xp + Mission 2,000 xp total xp = 31,000.

T20
Scout 99D97BA7 Level 7, xp 31,000, HD 7d8+14, Staminal 44, Lifeblood 14, Age 38, 5 terms, Cr 121,400. + Skills.

Now the skills have to be taken care of

Pilot-1, Rifle-1, Navigation-2, Medic-1, Air/Raft-2, Gunnery-1 Ship
The skill points should be divided in the following proportions.
1 part pilot, (There is no Rifle skill), 2 parts Navigation, 1 part Technical [Cascade] T/Medical, 2 parts pilot (Air/Raft), 1 part Gunnery and he gets a scout ship.

Hows that?
 
Interesting thread. Personally, here's what I do when I'm converting CT/MT in a pinch:

Stats:
For the six basic Traveller stats, multiply by 1.5 (round fractions down), and record the T20 stats. (Social Standing may be the exception, if the noble rank is required for the character concept. If so, then translate according to the table in the THB.)
For Wisdom, roll 2d4-5 and add the result to Intelligence (or Education, your choice). Impose a lower cap of 3 and an upper one of 18.
For Charisma, roll 2d4-5 and add the result to Social Standing. Impose a lower cap of 3 as above, and an upper cap of 18.

Terms:
Terms are then converted to XP, simply by multiply the number of terms by 5000xp. Adjust totals slightly if the character is borderline and you'd rather them be a level higher or lower than where the XP sets them at.

Skills:
Using the appropriate T20 class(es), determine skills and feats that best produce the feel of the skillset from the original character.

It's not official, but it's what I use, and it works well for most characters. And most importantly, it's fast and easy to remember.

Hope this helps,
Flynn
 
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