Being a level 7 spell, enchant weapon will be difficult to master for most characters. However, it can prove very useful, either for a non magic-based player to increase the enchantment on primary weapons (though this may take some time, since the failure rate will be very high) or for a magic-based player to enchant fallback physical weaponry. For any role, however, it is helpful for identifying weapons, since cursed weapons can be uncursed with this spell. This item does not exist in vanilla NetHack, but can be found in SLASH'EM and NetHack Plus.