Im old(school) enough to be a Motörhead fan. One song that I used to hear a LOT when I was young was “I am the Sword” from the album “Bastards”. If you haven´t heard about it, it might not have been available in your country. Due to the German label XYZ Music it was only widespread in Germany at first. But this post is not about albums, but about magical weapons inspired by the lyrics of “I am the Blade”. OSR-style, LotFP(tm) compatible. The magical bonus is in all cases incorporated in the weapons base damage.
“(…) I was the one that you didn’t see / I was the cut down to your bone / I put you there under that stone / I, I am the blade (…)”
The Unseen Blade
A long, straight steel blade, somewhere between a long dagger and a short sword. The simple handle is wrapped with leather, a round disk functions as the guard. The words “I am the one that you did not see” are engraved across the edge of the round guard. The Unseen Blade counts as a magical (+1) small weapon (1d6+1 base damage) that grants a +2 bonus to all Sneak Attacks made with it. When drawn within 20 feet of a designated victim, The Unseen Blade may bestow upon its wielder the equivalent of a 2nd level Invisibility spell. This effect may only be invoked in the nights of the new moon, and the wielder must be aware of this ability of the weapon.
“(…) I am the dream of the brave (…)”
Blood of Heroes
A sword with a gold-plated lion head at the pommel and engravings in form of a stylized crown above the cross-guard. It counts as a magical (+2) medium weapon (base damaged: 1d8+2). Once a day, when the wielder is outnumbered in melee at least 3:1, the Blood of Heroes may bestow upon its wielder an effect equal to a 3rd level Heroism and Army of One spell. The Blood of Heroes is a proud and unforgiving blade. If its wielder ever surrenders after it has been drawn, it will turn into a cursed (-3) weapon for this character until his or her death, and will never bestow its powers on this wielder again.
(…) I, I am the sword / I bring the fear of the Lord (…)
The Fear of God
A broad sword whose hilt and guard are formed to resemble a christian cross, with the the words “Fear Thy God” engraved into the blade (in Latin). It is a magical (+1) medium weapon (1d8+1 damage). If a Lawful wielder of this weapons becomes the target of a detrimental magic-user´s spell, the weapon will negate the spell once per day with an effect equal to a 4th level cleric´s Dispel Magic. To a character of Chaotic alignment the weapon counts as (-4) cursed weapon.
(…) I am the promise unmade (…)
A fine two-handed sword that has the words “The [insert noble line] must be removed from this land” engraved along the blade. The weapon was forged during a feud or civil war, and was crafted for this one and only reason. It is a magical (+2) great weapon (1d10+2 damage) that puts a 6th Level Geas onto anybody that uses it in an actual combat at least once. The geas is to remove those of said noble line from the land (killing them, driving them into exile, etc). The curse brought upon those that decide to ignore this obligation (that a character becomes immediately aware of) is that they shall know no friends in this land: all future random reactions of human and demi-humans cannot be better than Indifferent, the moral of retainers will will drop by one per day (if it was below 10 already) or week (Moral 10+). This curse will not affect the reaction of those not born in this land.
(…) Centuries pass, dust in the wind / I shall remain, shining in sin / The metal I am, the iron you feel / The song of the dead, the chorus of steel (…)
[It has no name]
A seemingly ancient iron sword that is never the less free of rust (and immune to the tests of time). It is a magical +3 medium weapon (1d8+3 damage). A Chaotic wielder will not age a day (neither natural nor magically) as long as the weapon is kept nearby, and may once a day cast an effect similar to a 3rd level Speak with the Dead on the body of somebody the character has slain him- or herself with this weapon.
(…) I am the ax / To cut down heroes like rats (…)
A worn but still sharp battle ax, with more than two dozen notches at its handle. Against human or demi-human foes of at least 4th level it counts as a +4 magical weapon (1d8+4 damage). Nobody will be able to make a notch into the handle without breaking it entirely (and thereby destroying the magic abilities forever), for it proofs to be harder than stone. When a human or demi-human of at least 4th level was slain with it, another notch will appear on the handle.