@ Wyldhunt
Ah yes, you're talking about that lookalike of mine on that other forum. He's always stealing my ideas.
You are correct though, I am pretty much revamping the game from the ground up. Maybe I should have started with the core mechanics rather than with the psychic powers, but in my defense I thought they would be easier than this.
Your layout is pretty good though. I like it, but I still like the idea of random numbers of wounds for perils though, to account for the randomness of the warp. And the difficultly rating idea is good too. I'm just worried about overdoing the number of rules within the system.
Honestly only play testing will tell.
You mentioned purchasing powers: maybe that can be combined with a masterly level? I mentioned this idea before in another thread of the warp charge of a power being its 'price' and the pyskers level being its 'currency'. So a level two Pysker could buy either one warp charge 2 power or two warp charge 1 powers.
Again though, I feel like I'm overdoing things.
The fact that Perils of the Warp exists at all reflects the dangerous and unpredictable nature of the warp pretty well. "You sure you want me to use my magic powers, boss? There's a nonzero chance that my head will explode." The thing about making it multiple wounds is that it really,
really hurts psykers in a potentially very unfun way. Even the current 7th edition Perils table only has one result that does more than a single wound to the psyker.
Here's the thing: A librarian or farseer taking a wound from perils hurts. It makes you go, "Ouch! I'm very nervous about continuing to use my powers with such reckless abandon!" A single wound gets that message across.
Taking two wounds means your librarian simply dies. He's gone. You put 100 points into him? Well your mildly bad luck and a completely average roll on a d3 says he's gone now. It gets even worse with more powerful (usually named) psykers. You took Ahriman? Sure, he's less likely to do to a single perils, but he still could. And when you lose him, you lose a much larger chunk of your army than a bare-bones sorcerer.
The warp is wild, sure, but that doesn't mean you have to add a bunch of random rolls to everything related to it.
I actually kind of like the idea of taking a page from the Fantasy Flight books and allowing psykers to intentionally cast more "safely" than normal at the cost of being less likely to cast the power. So you might choose one of three modes when casting a power:
Safe: Harder to cast the power, but perils aren't a thing.
Normal: Standard rules apply.
Super Saiyan: Much higher chance of perils or even auto-perils, but you can automatically cast the power.
The "Mastery Levels as currency" thing is a neat idea, but I'm not sure it would really work out. Looking at Farseers, for instance, many of their powers are WC2. So taking a classic combo of Doom and Fortune would be impossible, and you'd never know more than two powers assuming you're drawing purely from the Runes of Fate table.
For a librarian, you'd have to spend the points to upgrade to ML2 just to have the choice of purchasing half of the powers in the game.
So ML as currency for powers will significantly reduce the flexibility of psykers. It basically makes them worse across the board. Which isn't necessarily a bad thing if you want psykers to be worse than they currently are, but you should probably reduce their cost by a ton to compensate. After all, that ML2 librarian just went from having 3 powers (with psychic focus) to potentially having just 1. And that's after he paid for a second mastery level.
What I like personally is essentially the 5th edition way of purchasing powers:
*Psykers start at a lower cost than they are right now.
*All powers have a set points cost.
*Psykers can buy as many powers as they want (there's no reason for them not to learn new ways to use their abilities considering the variety of things we know psykers can do in the fluff/novels).
*You can only cast a number of powers each turn equal to your ML.
I'm tempted to change that last one to, "You can only cast a number of powers whose total WC equals your ML," but that unintentionally punishes things like librarians quite a bit.