I don't know how many people have discovered this, but I wanted to post it because I think it's funny and it's possible to do without mods. You can obtain the Silver Sword of the Astral Plane as early as Act I using the ability Command: Drop. This ability can be used by Clerics, Paladins, Fiend Warlocks. Bards can learn it too, but only much later. You'll also need about 3 Invisiblity Potions. I've been able to obtain a Silver Sword as early as Level 2 doing this.
At the Mountain Gate in the northwestern corner of the map, you find the Githyanki patrol where Kith'rak Voss will land his dragon. When you go there, you need to make sure Lae'zel is
not in your party or she'll become hostile and you'll be forced to kill her. Avoid walking through the gate and, instead, make your way to a ledge overlooking the patrol, pictured here:
Here I'm using Shadowheart to use Command: Drop on Kith'rak Voss. I've also had her drink an Elixir of Vigilance for a higher Initiative roll for when she enters combat. When you use Command: Drop on Voss, your chances of success will be very,
very low. This is because he is a Level 12 mob and, at this point in the game, your characters will only be about level 2-6. My Shadowheart had a Wisdom score of 16 and had a 12% chance of success when using Command. Most likely you won't get Voss to drop the sword on the first try, so you're going to have to savescum a bit if you want this to work.
No matter what happens, after you initiate combat, Voss will fly away. He won't fight you, but you
will have to deal with the patrol. This is one of the most difficult fights in Act I, especially if you're low level and don't have a full party.
Here, I had Shadowheart drink an Invisibility Potion before runnning far enough away to Flee. Combat will end as soon as you've fled and you'll have an easier time trying to nab the sword. For this, I had my PC drink another Invisibility Potion before sneaking down and picking it up. Note the Githyanki patrol will NOT pick up the sword. Sounds idiotic, I know, but they just leave it there for the taking and not even Voss will come back to retrieve it.
Yes, this is broken as hell, and I love it!
As soon as you pick up the sword, you will lose your invisibility. It's best to retrieve it with a character with a higher Initiative score which is why I used my PC (Rogue with 20 Dex). Pop another Invisibility Potion, run away, and Flee combat.
Now, a quick warning: if you bring the sword back with you and talk with Lae'zel, you will trigger some Act III comments from her. Be aware of this lest you get spoiled, you filthy cheater.
Note she'll also talk about your encounter, although her dialogue does not at all reflect what actually happened. It's crazy the devs didn't account for players doing this because Lae'zel
should be furious at you for what you did and utterly embarrassed that some
Istik disarmed a Githyanki Dragonrider with a Level 1 Spell.
Unless your PC is a Githyanki, you can't make full use of the sword's abilities. Silly Istik, Silver Swords are for Githyanki!
Generally, I just let Lae'zel have it. She seems pretty happy to use it...
Note, if you do the [History] check, you trigger the Act III dialogue. This is how you know you were never intended to obtain the sword this early because Lae'zel makes a comment about the
Githyanki Prince.
Be smart and make your wielder a Eldritch Knight or a Warlock with Tome of the Blade. Cast Bind Weapon on that thing and never let it leave your grasp! Don't be like Kith'rak Voss, kids.
It's hilarious to me how easy it was to obtain this sword considering a good chunk of Neverwinter Nights 2 is dedicated to the Githyanki dispatching hordes of soldiers intent on reclaiming one of them.
One last thing I should mention is that I've heard there's a chance that Voss will not spawn with his sword but will be carrying a crossbow instead. It's not clear why it's one or the other, maybe it's random. I haven't had it happen to me, so I might just be lucky. There's supposedly a workaround for this where you toss the Iron Flask into the patrol to summon a Spectator. Voss will attack it with his sword and you can try to disarm him after the Spectator is dead. I cannot confirm whether or not it actually works.