MechaPilot
Explorer
I have a hard time seeing how that encourages trying new things. there is no drawback, so the SAME thing would happen every turn, not new things. You might as well make it a houserule that any attack that hits by greater than 5 also reduces AC, because that's what's going to happen. If there is no drawback, why wouldn't I say with every attack, "I try to sunder." The called shot rule in AD&D seems set up for this exact type of scenario.
It encourages the trying of new things because there is no perceived punishment for the attempt.