Let me quote myself for a starter:
How to choose a name is up to you
Ok, now that out of the system, generating a letter to start with is not the worst way. I have in the past generated random letters and then looked at culturally appropriate naming tables for the game played (you can find a list of names in many game books), or one of the other methods I elaborated on in the answer I quoted from.
For a very random example, such a list of appropriate or common names for Cimmerians can be found in Conan - Adventures in an Age undreamed of (2017), p.48. Elfish names for Aventuria can be found in Aus Licht und Traum - Die Elfen Aventuriens (2006), p.57-58. Owen K.C. Stephens: By Any Other Name; in: Dragon Magazine #251 (1998), pp.52 is describing a method to generate random names from particles for elves in the Forgotten Realms.
Once you got your start letter, and maybe another one or two, you usually do have enough to find a name, but if you make complete alien names... go for all letters. Personally, I prefer to chuck in the name list of a game into excel and then draw a random name or name part from that hat, but you do you!
The mapping problem
Mapping letters do a D20 however is a little problematic, as some of the 26 letters won't fit. d20+d6, as you noticed, creates a skewed pattern and 1d20+2d6 is even worse. So, we need a method to map 26 letters differently.
Mapping by joining letters
There's a number of letters that can be merged into one number and then deciding which variant it is by rolling a different die. I would combine the following:
- I + J + Y - 1d6: 1-3=U, 4-5=J, 6=Y
- U + V + W - 1d6: 1-4=U, 5=V, 6=W
- S + X + Z - 1d6: 1-3=S, 4=X, 5-6=Z
This results in 20 letters with a slight skewing away from those merged letters, mapped as follows:
1=A; 2=B, 3=C, 4=D, 5=E, 6=F, 7=G, 8=H, 9=I/J/Y, 10=K, 11=L, 12=M, 13=N, 14=O, 15=P, 16=Q, 17=R, 18=S/X/Z, 19=T, 20=U/V/W
Mapping triplets skews the probabilities of the merged letters down, the rest is equally prbable.
Each letter has a binary value in ASCII. For us relevant is the center column: A is 0100 0001, B is 0100 0010, and so on till Z is 0101 1010.
To generate any of the 26 letters, you write down 010 and then throw 5 coins: Heads are 1, tails are 0. If the resulting number is not assigned as 0100 0000 and 0101 1011 or greater are, redo the roll, or assign special characters for like Æsc, the Umlauts Ä Ö Ü or diacretic like
There are 6 reroll events, and each other letter has the same probability.
Skewing for vowels
There are 5 vowels and Y, which can take a vowel sound, and 20 other consonants. Split the generation in two steps:
- first throw a coin (or use a different die).
- On Heads, you roll 1d6 mapped to A, E, I, O U, Y
- On tails throw 1d20 mapped to the remaining consonants.
This skews the naming convention to start with vowels 50% of the time for 8.3% per letter while every consonant has a 2.5% chance because the d20 and the d6 are flat distributed in themselves.
Using a different die to skew the probabilities alters the chances. I did not duplicate mathematically identical dice (e.g. 1 on 1d10 is the same as 1&2 on 1d20):
- 1-3 on 1d8 for vowel-dice results in 6,25% per vowel and 3,125% per consonant.
- 1 on 1d3 for vowel-dice results in 5.56% per vowel and 3,3% per consonant.
- 1-3 on 1d10 for vowel-dice results in 5% per vowel and 3,5% per consonant.
- 1 on 1d4 for vowel-dice results in 4.167% per vowel and 3.75% per consonant.
- 1&2 on 1d10 for vowel-dice results in 3,3% per vowel and 4% per consonant.
- 1 on 1d6 for vowel-dice results in 2,78% per vowel and 4.167% per consonant.
- 1-3 on 1d20 for vowel-dice results in 2.5% per vowel and 4.25% per consonant.
- 1 on 1d8 for vowel-dice results in 2.08% per vowel and 4.307% per consonant.
Black Excel Magic
Random Letter by Excel
Use a spreadsheet and fill in the following formula:
=FLOOR(RANDBETWEEN(1,26),0) This generates a number between 1 and 26, which can be easily mapped from A to Z without problems. The resulting distribution is by the nature of the generation flat.
Natural Distribution of Letters
If you are particularly adventurous, alter the formula to generate the letters by chance of them appearing in English:
A1:A26 - Letters A to Z
B1:B26 - each letter's probability
the field D1 will now spit out one letter from A to Z, mimicking the natural composition.
Or you look at this spreadsheet, where I did the dark magic for you. The spreadsheet also generates a 12-letter string with that method, which might be pronounceable or not. With a little letter shoving it can make a name if you are creative. If you don't like the generated seed, just wait a minute - I set up the spreadsheet to recalculate every minute or so.
The distribution is decidedly not flat, but skewed to the percentages given - ca 12% of the letters will be E, but 0.2 will be Z.
Random Name from the hat
Personally, I prefer a "name/name particle from the hat" method. It's actually simpler, and shown in the same spreadsheet on the 2nd page:
- Column A holds all the names or name particles that you like or that the book suggests
- C1 is
=RANDBETWEEN(1,COUNTUNIQUE(A:A)) and generates the number of a row
- D1 is
=Index(A:A,C1) and plucks the name from the A column.
Personally, I love this method, especially using name particles to generate characters for l5r games. Name particles are whole characters or syllables, that when combined create a full name. An example of taking 2 particles is also on the "name from the Hat" page.
Natural Letter Mapping with 1d1000
Using the natural distribution can be used with manual dice, as generated in the C-column with 1d1000 to allow the needed precision as quite some letters only have a rounded 0.2%.
0-85=A 86-106=B, 107-151=C, 152-185=D, 186-297=E, 298-315=F, 316-339=G, 340-369=H, 370-445=I, 446-447=J, 448-458=K, 459-513=L, 514-543=M, 544-609=N, 610-681=O, 682-713=P, 714-715=Q, 716-790=R, 791-848=S, 849-917=T, 918-954=U, 955-964=V, 965-977=W, 978-980=X, 981-997=Y, 998-999=Z.
The same as for the Excel-Variant applies. Shifting to letters you want is easy.
It's easy to alter the spread of letters to accustom your liking.
In need of 1d1000?
A d1000 can be done by rolling 1d10 three times and just writing down the numbers as they come: 000 is 0, 1-1-1 is 111, 9-4-6 is 946.