An interesting home-brewed rule idea in the OSR community, is the "Shields Shall Be Splintered" rule. Basically, this allows the character to sacrifice their shield to ward off a damaging blow that would have hit them. The rule is quick, simple, and neat. Without complication, the character makes a decision and pays a price (losing their shield) as a consequence.
But then the argument goes further. If you can sacrifice your shield, can the character not then sacrifice other items of armor or equipment to fend off blows? Before a DM says yes, they should look at the ramifications of their decision. A character could first sacrifice a shield, then a weapon, then maybe their armor, round after round, prolonging the inevitable. While some DMs might not mind this at first, they would soon see clever players staying alive long enough by making these sacrifices, all the while allowing their team mates time to hack the enemy to pieces. The system then because abused.
How can a DM prevent this from happening, without throwing away the rule entirely? A simple modification comes to mind that may serve the purpose. While sacrificing a shield may be done fairly automatically, what if the character must make a Saving Throw (vs Death, if your campaign uses separate categories) for any sacrifice afterward, but may do so only once? Failure of this Save, means that the character takes damage as if hit by a Critical (however your DM handles them in the campaign). Basically, the warrior attempts to use his sword to fend off the final blow, but the orc chieftain's axe breaks his blade and cleaves his skull in twain!
Going for Broke is not the same as using the Parry rule. The character is attempting to sacrifice (make a Save) a specific piece of equipment (besides a shield) in an attempt to live to fight another day.. or round, as the case might be.
The DM may allow a bonus to this Save depending on the item being sacrificed. The more important, or powerful the item, the greater the sacrifice.
The Rule In Action:
Angar, issues a challenge to Bloodeye, in an attempt to draw the orc chieftain out into a one on one fight. Bloodeye, accepts by rushing out and hurling his massive spear at the barbarian. Angar, realizing the spear is about the drill a hole through him, sacrifices his shield to intercept the spear's flight. Bloodeye's spear drives through Angar's shield, making it useless, so the barbarian casts it aside. With sword in hand he rushes the powerful orc.
A few rounds of furious blows are exchanged, with each combatant getting slowly whittled away by the other. Soon, Angar, finds himself backed against a rock wall, with no means to escape. Bloodeye, seeing his victory at hand, swings his mighty axe for the last time. Angar, chooses to sacrifice his father's sword, and attempts to Go for Broke. The player running Angar, rolls a Save.. and succeeds! Angar, throws his ancestral blade up in one last ditch effort, and deflects the deadly blow at the last second, even as the blade of his sword shatters to pieces. Bloodeye, roars in anger at being denied the satisfaction of seeing his foe's head separated from his body.
Desperately, Angar, draws his dagger.. (having won initiative this round).. and drives it into the massive orc's heart!