If you need a random generator but can't roll dice or can't (or don't want to) access electronics, you already carry a d60 with you - or at least I do, with the seconds clock on my trusty $10 digital watch. This is especially great if you're solo roleplaying on a walk or at work, or perhaps if you're playing with others while walking or in the car or in just about any impromptu situation.
The easiest use for this is as a d6, a d10, or as a d6xd10 oracle, with 0 treated as the highest pip value. (As long as you aren't "rolling" too frequently, you can also make Ironsworn-style rolls with a glance, where the last minute of the seconds and minutes are the challenge dice and the tens digit of the seconds timer is the action die.) Knowing a few lists with an obvious/familiar order and 5, 6, 9, or 10 values (if one lower, let 0 = go with most appropriate) means you can be pretty flexible about this. Here are a few:
the universal d6 oracle that's been independently invented a zillion times, e.g.
- no, and
- no
- no, but
- yes, but
- yes
- yes, and
dnd stats (d6) or WoD stats + willpower (d10)
mtg colors
big five personality traits: d10, alternate high and low, OCEAN order
enneagram types: d10, 0 wildcard
dnd alignments: likewise
If you're familiar with the tarot, such that you just know off the dome what a seven or swords is or whatever (I don't), you can make :00-:19 the major arcana, drop the minor arcana nobility, and make the :2_s, :3_s, :4_s, :5_s the number cards of your suit of choice.
The Pathfinder Harrow Deck is basically already this, since the suites are just dnd stats and the "ranks" dnd alignment! (As before, turn the list of 9 into 10 via 0 digit as wildcard.) I'm tempted to familiarize myself with it because then I get an instant image or more complex tarot-y association that requires a little less brute force recall than actual Tarot, even if the original version is richer.
Oath boardgame suites (hearth, order, discord, nature, arcane, nomad) though I don't have a great intuitive sense of how to order them other than by memorizing in brute force
List your own!