The Lantern in Combat

Domenico Angelo's The School of Fencing (1787) includes a section on how to confront an opponent who employs a “dark lanthorn” – a lantern with a panel that slides to block the light.  Evidently, footpads would equip themselves with a sword and lantern in order to commit their depredations.  According to Angelo, “there are severe punishments inflicted upon on those who are found sword in hand with a dark lanthorn...”  Reportedly, such a criminal would keep the lantern's panel closed, thereby maintaining darkness.  When the robber approached close enough to shine a beam of light into the victim's eyes, he would open the panel.  This would temporarily blind the victim, thereby facilitating the footpad's goal.

If such tactics were viable in the real world, why not apply them to dungeon delving?  Subterranean entities with sensitive eyesight might be particularly susceptible.  How would the mechanics work?  Perhaps, first of all, a successful 'attack' should be made on the part of the lantern wielder.

Starting with Moldvay's D&D and continuing with subsequent editions of 'basic', a 'Light' spell cast at a target's eyes would cause blindness for the duration of the spell (assuming the target fails a saving roll vs. Spells).  “In D&D BASIC rules,” the spell description states, “a blinded creature may not attack.”  This effect may be more severe than what a non-magical light would be expected to accomplish; yet it provides a precedent.  Edition 3.5 indicates that a “dazzled” character has an attack roll modifier (both melee and ranged) of -1.  Additionally, the Armor Class of a “blinded” character is detrimentally modified by 2 (and no Dexterity bonus is applied).  In fifth edition, attacks by a blind character “have disadvantage” while attacks against a blind character “have advantage.”  The fifth edition “condition” of blindness seems appropriate for our purpose.  But what about a saving throw?  For 'basic', like the 'Light' spell, a saving roll vs. Spells may be apt.  The 3.5E 'Sunburst' spell allows a Reflex save to avoid blindness whereas the same spell in 5E indicates a “Constitution saving throw.”  A blinded character is entitled to “another Constitution saving throw at the end of each of its turns” (to a maximum duration of 1 minute I suppose) in order to recover.  I am inclined to favor a Wisdom saving throw rather than Constitution, since Wisdom governs perception.

Depicted below is a lantern shield, a 'real world' weapon that incorporates a lantern for the purpose for blinding or dazzling an opponent.  It seems rather abundantly accessorized to be of much practical value, still they would not have been made if there was no demand for such things.  Seemingly, lantern shields were not intended for combat but rather intimidation.  Of course, in an elfgame, there is nothing to prevent a lantern shield from being a common piece of adventuring equipment.