by Hermjard
Hmm, let me ask a assume some things from your answer. You compared exchanging the dice with buying dice. I assume, that means:1) Dice, you got by exchange must be used in that action, directly after they were exchanged. They cannot be "stored". That is presumably also the reason for the limit of three dice.
2) You are not allowed to manipulate exchanged dice with influence (i.e. the dice, you got by exchange, do not count as your own).
3) But the dice, you gave by exchange, are counted as own dice for the receiver? And he is therefor allowed to manipulate them later?