Ditto on Fate points forcing a reroll of a crit from a foe.
Every level we refresh the pool.
To calc, the PC gets to roll a die closest to that level count, if even. If odd, we add +1 to the roll. So Level 6 is a six-sided die roll to see how many are recovered.
Previous points are lost so they do tend to get used to add a flourish to attack/crit/MM results.
We use them closesly as per D&D Eberron with edits, too.
We also allow them to be used to add a D10 to the result of any roll - needs to be declared before knowing a Pass/Fail result re:MM Table that I use for almost every skill Static or otherwise, along with how many are to be used(down to 0).
===MM Table % results are rolled under/over to achieve 100% success or part of it in an extended round maneuver(Lock Picking); so roll on MM table with mods, generate original % result, then roll a second time to get under/over to be successful = 20% means roll under 20 or over 80 | 70% means roll under 70 or over 30 - player chooses for flavour.
Some Players never wanna roll low, haha.
For extended round results, any MM chart original % that is less than 100% can add to the time it takes someone to achieve a full end result.
So instead of complete Pass/Fail after the second roll to confirm, the difference of the original % from 100% is what is still needed to complete the action - usually used in picking a lock/disabling a trap, etc. It adds to the tension escaping and getting through an obstacle with foes on your tail===
If spent(and only if spent) and RR still fails, I take an extra Fate if player desired, to negate the effect of the result and reroll but the next effect is locked in.
For deaths that do occur still from this locked in result, no matter what intervention happens, I tell the PC we can deplete his/her pool of theirs down to 1 - the minimum per session that gets replenished to 1 upon next game, so there is always the chance of help.
However, once Fate points are at 0, the PC is "naked" and whatever befalls them thereafter is a done deal - they can only cheat so many times, haha.
EDIT:
To answer your question, haha, we have players with dead PCs roll up a new character with midlvl-point XP at one level less than lowest party PC possesses.