[W]e get pleasure when our (subconscious) expectations of reward are met, and we feel upset when those expectations are dashed. Additionally, we get extra dopamine when the reward is surprising. So, what we like, from most to least:
-2 Surprising disappointment
-1 Predictable disappointment
+1 Predictable confirmation of expectations
+2 Surprising confirmation of expectations
1e D&D is a hulking eldritch megabeast born from a mad wizard’s experimental combination of surprising rewards and surprising punishments.
4e repudiated randomness for sanity, balance, and survivability. On the whole, 4e is stronger for it.
Treasure, though, is an area where randomness should reign.
Early-edition treasure is a Vegas slot-machine – a slot machine whose every third coin is horribly cursed, but that just adds to the allure of Vegas. The random wackiness of treasure makes a nice counterpart to the steady, predictable advance of XP and character level. In fourth edition, treasure is also steady and predictable: the treasure and levels subsystems advance in lockstep like two steady, predictable oxen yoked together. Still, for compelling gameplay, give me the Vegas slot machine.**
I started using a homegrown random-treasure system shortly after 4e came out. I’m interested to see the Essentials DM’s kit, which is supposed to introduce an official random-treasure system. Hopefully it’s as good as or better than mine. It won’t be the first time that 4e errata has un-houseruled my houserules.
* Isn’t that what science is usually used for?
** I believe that, during the course of this analogy, I yoked together an ox and a slot machine, which is a win for the analogy and for D&D! Use that in your next encounter.