Alex
Arcane
When I was around 15-16, I was DM at ADD in the Dark Sun universe. I was not a great DM, pretty bad even, and a “rules are rules” one.
How is that being a bad DM?
In Dark Sun, all characters have one random psionic power. One of my player got super lucky and ended up with “disintegration”. My (mostly combat based) scenarii were sliced through, and the character even one shot a Drake that had been met due to me using (« rules are rules ») the random encounter table in the Dark Sun rule book.
Until that day where he fumbled a desintegration roll and disintegrated himself in the middle of that large mountain.
« Rules are rules » goodbye OP character.
(snip...)
I should have been clearer. I love a lot of the stuff on the psionics handbook. But the system it presents is actually really a bad fit for D&D. I mean, it works great if you take the powers as an add-on to an existing class, as a multi-class or a wild power, or as in the Dark Sun example you gave. But they don't scale well at all. The powers don't get stronger with levels and the best you can do is increase your chance to use them successfully by giving up a new power for a measly +1 to the roll.
As for being unbalanced, I don't consider that too important. Old D&D wasn't too big on the idea of big showdown fights. I mean, people did it all the time, of course, but a whole lot of the design philosophy of the system is geared towards fights being only another way to create problems for the player to solve creatively, rather than an actual strategic game of well defined moves. Disintegration can be a really good tool in the right hands, but it is still only a tool, and you can still easily die to a trap, or to an angry mob of creatures, or whatever. But yeah, if you do mostly combat adventures, it won't work as well.