They could use a nerf, yes.

I agree that they're too good right now, since they make almost everything trivial once you have them, and there's no reason not to just spam them for the rest of the game. Not sure about the specific stats they should have; I'd be more inclined to give them damage dice similar to existing high-end ammunition. I like True Aim having a huge +hit though.

I'm not exactly sure in which world are you able to clear a GUV with them as both projectiles don't have a 100% return rate (I'm not talking about Dx-dependent catching).
This goes to all of you, how can you say you can spam them the whole game when every 1 in 7 or 8 shots it doesn't return?
I'm actually quite afraid to use either missile in a vault because if it chooses to not return, it will get swarmed by monsters quickly or picked up and I might as well have to clear half the vault in straight melee or using normal arrows just to get it back.
Hence, I'm saving this up for the tougher guys which by definition reduces how often it's used and how often it gets lost.
In this case it's not actually that OP, it gives you the much needed advantage against nasty stuff like lich royalty.
I don't think that overall either projectile needs a nerf, they're not guaranteed to be found and when they are, you might as well be playing a duelist or any other char that doesn't use archery that much so they're not as advantageous.

I'd say this: if the missiles' stats are adjusted as suggested by Ln, make the return rate 100%, so they will ALWAYS return and not drop somewhere in the middle of a horde of ancient karmic dragons that just got summoned by a lich king.
Otherwise suggested nerf is too harsh in my opinion. No from me.

I think a nerf is in order, though I kind of agree with Blasphemous that the suggested reductions are perhaps a little extreme. At 3d5 with no slaying powers, for example, True Aim is not substantially advantaged compared to regular eternium arrows, scurgari of returning, the black torc, or even a regular boomerang.

That is kinda the point.
Better than eternium arrows since they return.
Better than scurgari of returning/boomerang since they are indesctructible.
Better than black torc because they have weapon skill.

2Blasph:
Not returning 1 in 7/8 times is not what I have experienced. The fact that I did clear a GUV still stands. Backtracking and luring to a different level was required, but the sheer OPness of True Aim allowed me to dispatch any summon (including diamond golems and molochs) which basically means that you don't need anything except True Aim.

My opinion is that True Aim and Thunderstroke are just below AoTME. If you have <20 Dx everything else in the game (excluding ToTRR) is less effective. This includes Executor, Vanq and slaying ammo.

I think it'd be really good to nerf them, but I'm not sure by how much. 3d5 (9 avg) sounds a bit low to me. A good comparison is the dwarven rune axe, which is also indestructible, has no slaying powers, returns, is guaranteed and easy to get. That one deals 3d8+4 damage as a missile (17.5 avg). Although True Aim can get another damage from your bow, which the axe obviously can't.

These artifacts went from something highly disappointing to get (pre)crowned with to very good, are you not happy about that?

They are not guaranteed to be generated, return when shot or even hit their target. That's balanced enough as far as I'm concerned.

How about instead of returning Thunder stroke can hit multiple targets. It would be the same as level fifty archer power but for every class with the artifact. So a nerf that dosent help high level archers but may help low to mid level players clearing vaults and temples.

If those are the only criteria for balance, they could do 1000 damage per hit still be balanced.

Thunderstroke has the second highest base damage of any weapon in the game, higher than the ToTRR, and only slightly less than the AoTME. And that doesn't include the crossbow. Plus it gets missile crits that do much more damage. You could halve the damage that these artifacts do and they would still be top tier.

This.
IMO, if greater identify says that "This weapon returns when thrown.", then it really should return. Every time.

"These are garbage, they need to be buffed"

... a year passes

"These are too good, they need to be nerfed"

Slaying ammo is always better against specific monster types. Do you want to nerf that too?

Now that I've given it some thought it's a pretty difficult argument.

Neither of them are guaranteed. Any amazing weapon you might come across is not guaranteed (save the tridents and the axe and the daggers, and they all require some work to get them). So they should be kind of silly powerful. The 'problem' here imo is if you get either of them too soon it makes the whole game a bit trivial as they are so supergood at that point of the game.

Just a silly thought: how about ie make true aim dmg x d 5 where x is lvl/3 (and cap it at 15d5 or whatever)?

Also I'm not sure if i'm the right person to even comment here as i've only got them once in the newer releases (p23) and that time I was an archer and I also got the arficat bow.. so maybe I was just playing a class that is supposed to be super op with bows and happened to get the perfect combo pretty early on so..

Not sure what you're trying to say. They were garbage, but making them returning was an enormous boost. The difference between a one-shot piece of ammo and a returning one is huge.

It actually happens really often that a weak game feature gets a buff that turns out to be too much. Aka overcompensation. The remedy is to apply a milder buff, aka balance. Nothing contradictionary about that.

No, slaying ammo is not always better. That's the whole point. The base damage that True Aim and Thunderstroke have is currently so enormous that they are often even better than specific slaying ammo.

Blessed True Aim is roughly equivalent to undead slaying ammo when used against lich royalty in a D:45 GUV, perhaps a tad little less effective, from my recent experience.

blessed slaying ammo is definitely better than blessed true aim, not by much, but still clearly.

Slaying ammo is only marginally better, generally, unless you have quite high stats.

An arrow of undead slaying does 2d4+3 damage (average 8), and scores crits that do 3-6x damage (average 4.5x). So an arrow of undead slaying does 36 damage on average. True aim does 15d5 (average 45) damage. So base damage of True Aim is actually higher than slaying (and Thunderstroke is much higher). But the crit multiplier affect Dx, skill, and bow damage bonuses. It's only when these are accounted for that slaying ammo looks better.

Blessing affects both in the same way, so I'm not worrying about that.

Slaying ammo is "better" only because it guarantees a critical hit. Critical hit with True Aim / Thunderstroke is ridiculously powerful, and with Find Weakness 100, Cat Ring and BoW...

Well, slaying crits on missiles are actually better than regular crits (3-6x vs 2-5x), but yes, crits with True Aim and Thunderstroke are ridiculous either way.

Missile weapons are way overpowered in ADOM in general. Not so much due to intrinsic damage (though it helps), but because the vast majority of monsters do not have ranged attacks, and the handful that do are rather pitiful. Consider demons, for example, that can hit you pretty hard, curse you, drain stats, confuse, etc, all from melee range, are completely powerless when confronted with, I dunno, thrown rocks? If you want to solve this problem, look into giving some monsters a really nasty ranged attack, coupled with a rather weak melee attack.