I have been a proponent of keeping dice in your pocket (and practicing what I preach) for some months. Ever since I read this, in fact. Yes, I have a dice rolling app on my iPhone (Mach Dice), but it's not the same.
Keeping dice in your pocket, however, begs the question: how many dice and which ones?
Before I go any farther, let me recognize that this is a really silly post.
And now that I have that out of the way... Typically I would suggest you keep a d20 and 2d6, but that's primarily because of the kinds of pocket games I like to play. Recently someone asked me which dice I would carry if I needed to replicate all the polyhedrons. There are actually several answers to this question, and you can go as low as two dice, but I settled on three: the d6, the d8, and the d20.
|The perfect pocket dice?|
Let's build the "dice chain" a step at a time.
You got em. Those are your baseline pocket dice.
You can get a d12 using a simple high-low method. Roll the d6 and d20 together. Read the d6 and add 6 if the d20 is high (11-20). This is more intuitive than it sounds. Try it!
Note. I am going to suggest a very similar sort of procedure for a lot of these, which is to add or subtract a big number (often the highest value of the die) to/from itself based on the result of another die. I don't know why this is intuitive, but it is how my brain works at least.
For a d10, just roll the d20. If it rolls high (11-20), subtract 10. To get a d100 aka a d%, do that twice and the first roll is the "tens column." (Note. Another way is to roll the d20 and ignore the first digit, treating a 0 as a 10. I thought that would be easier, but somehow my brain works better with the high-low die because it's weird to roll a 10, ignore the 1, and then still treat the result as a 10.)
To get a d4 you roll the d8 and subtract 4 if the result is a 5 or more (so that 5 to 8 becomes 1 to 4).
Why not d6-d8-d10 or d12-d20?
As I mentioned above, there are other combos you can use to replicate all the dice. I chose the three I did for a couple of reasons: shape and utility.
All three dice have a distinctively different shape, one you can tell at a glance. In fact, I think of them as square (d6), diamond (d8), and circle (d20). If you squint at them, that's what you see. On the other hand, a d12 and d20 often look very similar at a glance. As do a d8 and d10.
I personally dislike the d4, primarily because it is small and hard to pick up, but also because it can be a little awkward to read. That die was never in the running in any case!
I chose the d6 over the d12 and the d20 over the d10 because those seem to be the most common dice used by games. In fact, original D&D only uses those dice.
But what about those funky dice? Can I get those too?
d2 roll any die and use low (1) or high (2).
d3 is most commonly rolled with a d6 anyway. You can use the 1-2=1, 3-4=2, or 5-6=3 method if you like, but I like just saying that on a 4+ you subtract 3.
d5 roll the d6 and reroll if you get a 6.
d7 roll the d8 and reroll if you get an 8.
d14 this is the most awkward one. I would probably roll a d6 for low-high and a d8, rerolling any 8s. If the 6 is high, add 7 to the d8 result.
d16 as per the d14, roll the d6 for high low, but this time just read the d8 and add 8 if the d6 is high.
d24 roll a d6 and a d8. To the result of the d6, add 6 if the d8 reads 3-4, add 12 if the d8 reads 5-6, and add 18 if the d8 reads 7-8.
d30 roll a d20 and a d6. Ignore the first digit on the d20 (gives you a 0-9, but of course you read the 0 as a 10). The d6 tells you to add 0 (1-2), 10 (3-4), or 20 (5-6).
I think we are all dumber now. Thanks for sticking this one out! :D