Another easy option for rolling a N-sided die is a N-sided prism, like a pencil that you roll on the table that can only come to rest on one of N sides (and never on the tips). With 3 sides it becomes a triangular prism that doesn’t quite roll as well as we’d like, but it’s doable.
Yet another option is a spinning top with N faces, where you can set N to whatever you want that’s >= 3.
But you’re right that in practice, probably re-labeling an existing dice, like relabeling a d6 as [1,1,2,2,3,3], is easiest.
Another easy option for rolling a N-sided die is a N-sided prism, like a pencil that you roll on the table that can only come to rest on one of N sides (and never on the tips). With 3 sides it becomes a triangular prism that doesn’t quite roll as well as we’d like, but it’s doable.
Yet another option is a spinning top with N faces, where you can set N to whatever you want that’s >= 3.
But you’re right that in practice, probably re-labeling an existing dice, like relabeling a d6 as [1,1,2,2,3,3], is easiest.