So in normal life, people say things like 'I'm not buying that shirt, it's ugly' or 'these pants make me look fat'.
...
Gawd, I loooove Enworld so much
In normal life there hasn't been a five year campaign, sometimes organised, and that often resorts to outright and unequivocal lies even when corrected with references and page numbers to marginalise people wearing specific shirts. (Actually, yes there has now I come to think of it in a number of cases including what colour belongs to what gender - and those deserve pushback too). And yes, I say five year when 4e is only four years old for a reason. If you want evidence, try reading grognards.txt on Something Awful.
In order for a fatigue point system to work these things have to be true...
1. The power has to at least seem fatiguing. No "Come and Get It".
2. All powers are restored after 10 minutes. Long term fatigue is not well modeled by powers being on or off. Thus dailies in particular are the most dissociative when it comes to martial activity.
3. Each individual power is not expended. Rather the pool of powers expend some kind of fatigue points. If encounter 1 uses X energy and encounter 2 uses X energy then if I have X energy left I can do either. If I don't then I can't do either. Being able to do 1 and not 2 is dissociative.
Now I'm not saying I love the above approach. I was offering a fig leaf to see if anyone on the other side thought it was interesting. I mostly prefer at-will powers for martial types.
1: Why? You are modelling the process at the expense of the outcome. See [MENTION=3887]Mallus[/MENTION]'s neat summary of why this is bad.
2: Here's a baby with bathwater issue. Because it doesn't do it well doesn't mean it shouldn't try. But this is provisionally acceptable.
3: This can happen if and only if there is another constraint presented on which power you are allowed to use. Spamtastic approaches you offer that reward merely doing the same thing over and over again are not acceptable.
You can possibly fix this with a second mechanic - for instance a roll for each combination to determine whether you gain the advanced version of it this turn - and you roll before picking what you do. And then throw in a fatigue point system. But you absolutely must have an incentive mechanism to not always do the same thing. If I can replace my fighter's play in combat with three lines of code this is unacceptable.
So, for a bivariate system you can have:
1: 3 fatigue points. Each Exploit costs a fatigue. At the start of your turn roll to see which exploits are augmented - the augment roll is 1d6 per exploit.
Exploit 1: Stop Thrust. Reaction triggered by being hit. Augmented on a 5+
Unaugmented: Make an attack agaisnt the enemy that does damage equal to your strength modifier if it hits. If this damage reduces the attacker to 0hp, the attacker only does half damage.
Augmented: Make a standard attack against the attacking enemy. If this damage reduces the attacker to 0hp, the attacker only does half damage.
Exploit 2: Through the Ranks. Augmented on a 4+
Unaugmented. Make a standard attack against your first enemy. Then move 5' and make a standard attack against a different enemy. Your first target gets an opportunity attack against you even if you didn't move.
Augmented. Instead of moving you shift and do not take an opportunity attack.
Exploit 3: Knock Them Down. Augmented on a 4+
Unaugmented: Make an attack against your enemy. On a hit you knock them prone and they take damage equal to your strength modifier.
Augmented: After knocking them prone you may follow up with your weapon and make a standard attack against them.
