Least sacred cow in D&D?
Orcus.
Just 'cause no one else has suggested it, 3/3.5 initiative. It penalizes or rewards a player over and over for the results of one roll, spread out over however many rounds of combat. Most other effects (poison onset, charm, some illusions) allow at least one other save during their duration, which then has class level or HD adjustment if it's Fort, Will, or whatever.
Is Improved Initative and/or Dex mod a Save vs. Going Last?
And in higher levels, is initiative itself a Save vs. Death? If whatever that hostile can do to you first kills you, that might be what it amounts to.
Delaying or readying actions doesn't always rectify this - just look at the number of rules threads there are about that here. Cyclical init is a boardgamey convention, one that cuts back on bookkeeping, but that doesn't allow PCs to do something clever that gets them an edge when responding to attacks. They can set up AoO, or run for it and hope for better init later, but if they can't they're pooched in a way no core class ability or item or spell can really fix.
Orcus.

Just 'cause no one else has suggested it, 3/3.5 initiative. It penalizes or rewards a player over and over for the results of one roll, spread out over however many rounds of combat. Most other effects (poison onset, charm, some illusions) allow at least one other save during their duration, which then has class level or HD adjustment if it's Fort, Will, or whatever.
Is Improved Initative and/or Dex mod a Save vs. Going Last?
And in higher levels, is initiative itself a Save vs. Death? If whatever that hostile can do to you first kills you, that might be what it amounts to.
Delaying or readying actions doesn't always rectify this - just look at the number of rules threads there are about that here. Cyclical init is a boardgamey convention, one that cuts back on bookkeeping, but that doesn't allow PCs to do something clever that gets them an edge when responding to attacks. They can set up AoO, or run for it and hope for better init later, but if they can't they're pooched in a way no core class ability or item or spell can really fix.