d20 to CODA?

[AslanC]

Has anyone worked up a good conversion for this?

I tried doing a thread search but since d20 has only 3 letters, the search wouldn't work.

Anyone?

[KillerWhale]

I wanted to do it but never found the time (two parallel campaigns in two completely different universes take time )

The first stages of what I thought was that the skills and attributes could be mapped pretty easily. What needs some more reflexion is the mapping of D20 to 2D6. I see two approaches:

- Consider D20 is basically a "flawed" system, since using a linear probability function (equiprobability of all numbers: as much chances of having 1 than 10 or 15) in a RPG is bad idea, and CODA has it the right way (the average is easier to obtain than the extremes).
That approach assumes we don't care at all for the D20 function and map the skills and attributes proportionnally (roughly, transfer D20 to CODA means multiplying by more or less 1/3).

- Consider D20 and CODA's proability functions work fine in each system. Then we have to convert D20 to CODA with respect for both functions. That means we have to transform D20's linear function to a binomial one (like CODA's). Let me explain with an example why this is different:

-> Aelwyn, my lv 6 wizard, takes a rank in Spellcraft checks, passing from 9 to 10. That doesn't mean a great improvement - his results range from 11 to 30, all with equal probability. The important thing is: The DC scale is linear too. In D20, you have to buy many ranks in skills to make a real difference.

-> Graldak, my Caitian security officer, passes gambling from 7 to 8. Most of the time, he will roll a 7 (most probable with 2D6), thus increasing his average rol from 14 to 15, which might matter since 15 marks the passing of another difficulty level. In CODA, the TN scale is linear too as in D20 but the probability function of the dice is not.

Obviously, one approach is easier than the other, but more than that, I think doing a conversion means thinking deeply of the "philosophies" of both systems.

I'd be glad to help writing or working on a D20 to CODA conversion

[Lancer]

Originally posted by KillerWhale
In CODA, the TN scale is linear too as in D20 but the probability function of the dice is not.

Only if you disregard all the possible modifiers, from lack of tools or fatigue to professional abilities and edges. Coda has lots of modifiers that could apply to either the check or the TN, so I wouldn't consider the TN scale of Coda Trek to be completely linear - it can be, but it must not always be that way.

[Grutos]

Good question. Being a die-hard DnD fan from 1st Edition to the new 3rd Edition (finally started to incorporate a lot of good house rules!!), I'd be interested to see a solid conversion between the two systems. I think that many of my Fighters/Barbarians and even my Mage could convert over to LotR's Coda system rather easily with Skills/Feats/Attributes, but not quite sure how some of the rolling would work. (Haven't tried ST yet, but perhaps my Smuggler Captain in SW could transfer over with a bit of work for a session or three).

[buck rogers]

The easyest way system is to take the total Expeience points for your d20 character find the square root. Then multiply that number by 75. This the right amount of experience in Coda. As far atributes they should be figured at aprox. sixty percent of the d20 stat. As far as the rest that should fall into place as each game system has its own unique way of representing various secondary attribrutes like hit points or wound levels. for this use the experience points to figur the amount of Advancements or what Level the character should be. Class or Profession should be easy to figure out as should the skills.