[AndMetal]

Haven't compiled and tested, but this one wasn't too complicated.

In zone/attack.cpp, change this

		//riposte
		if (damage == -3)  {
			if (bRiposte) return false;
			else DoRiposte(other);
		}

		//strikethrough..
		if (damage < 0 && !bRiposte) {
			if(MakeRandomInt(0, 100) < (itembonuses.StrikeThrough + spellbonuses.StrikeThrough)) {
				Message_StringID(MT_StrikeThrough, 9078); // You strike through your opponents defenses!
				Attack(other, Hand, true); // Strikethrough only gives another attempted hit
				return false;
			}
		}

to this

		//riposte
		bool slippery_attack = false; // Part of hack to allow riposte to become a miss, but still allow a Strikethrough chance (like on Live)
		if (damage == -3)  {
			if (bRiposte) return false;
			else {
				if (Hand == 14 && GetAA(aaSlipperyAttacks) > 0) {// Do we even have it & was attack with mainhand? If not, don't bother with other calculations
					if (MakeRandomInt(0, 100) < (GetAA(aaSlipperyAttacks) * 20)) {
						damage = 0; // Counts as a miss
						slippery_attack = true;
					} else DoRiposte(other);
				}
				else DoRiposte(other);
			}
		}

		//strikethrough..
		if (((damage < 0) || slippery_attack) && !bRiposte) { // Hack to still allow Strikethrough chance w/ Slippery Attacks AA
			if(MakeRandomInt(0, 100) < (itembonuses.StrikeThrough + spellbonuses.StrikeThrough)) {
				Message_StringID(MT_StrikeThrough, 9078); // You strike through your opponents defenses!
				Attack(other, Hand, true); // Strikethrough only gives another attempted hit
				return false;
			}
		}

This should allow you to avoid ripostes if you're attacking with an offhand weapon, but still allow Strikethroughs as described on Allakhazam.