I hate keeping up with the HP loss over multiple turns of AD&D’s version of the sword so I came up with this:
This fearsome short sword is a +1 magical sword that inflicts terrible weeping wounds that are very difficult to close naturally or otherwise. The victim suffers a condition in which up to 4 points of healing are negated per die of healing applied, whether natural healing, that of a healer, a potion, spells, or a troll’s regeneration. This condition persists until the victim is fully healed (at 100% HP) as the wounds inflicted by the sword are the last to heal.
Example 1: Albrect the Mighty is struck by the Sword of Wounding for 4 points of damage. He promptly drinks a healing potion which normally heals 1d6+1 HP. The roll is 3. Up to 4 points of healing are negated so the potion heals nothing.
Example 2: Feeling a bit worse for wear Albrect rests for a day and would normally recover 1d3 HPs. The roll is 1. Up to 4 points are negated, so he does not heal at all.
Example 3: Becoming a bit concerned that his injuries are not getting any better, Albrect visits the Temple of Our Lady of Infinite Healing where the high priestess (after a generous donation) hauls out the big guns and hits him with a Cure Critical Wounds which in this case heals 4d6+7 HPs. The die rolls are 4-4=0 2-4=0 2-4=0 6-4=2. So 0+0+0+2+7=9 HPs healed and Albrect’s wound closes as he is restored to full HPs.
I wonder would it be worth it to track the Sword of Wounding damage separately and confine the anti-healing effect to just that damage?