MAngband

A lot of the ego weapons/missiles I have found with my current warrior have gotten the "extra dice" property: I've seen a lot of stuff like a dagger (2d4), bolts (2d5) and so on... However, each time I leave the game and come back all those increases in dice seem to be lost. Sounds like a weird bug...
Probability of getting extra dice shouldn't be that high anyway, maybe that's the reason.

A few people have mentioned this.  I'll look into it.

- Jug

I have still yet to see an example of this where the reason hasn't been that the odd hit dice are due to the item being an artifact.

If anyone does find an item with odd hit dice, give me a shout in the game and I will take a look at it.  Until then, I'm going to put this down to artifacts and too much beer whilst playing.

Of course that's very Ironmanish.  All real Ironmen play whilst completely drunk.

- Jug

Totally agreed.
To me all lxbow's are x4 and all long swords 4d5. If they don't haste me I just assume my strength has been drained and that the 500 healing pots are slowing me down.

I'll try to pay more attention to extra dice though.

- Warrior

There is a VERY small chance upon item creation that it will have an extra die or side. It is possible.

Good to know.  I'll stop accusing players of being drunken hallucinating mad men.  ;D

- Jug

i just found a tulwar of extra attacks with 3d4 hit die. is that what you guys are talking about?

Yes.

Thus saith the 0.7.2a Source, in the function a_m_aux_1, from the file src/server/object2.c, lines 1890 through 1894:

[tt]/* Hack -- Super-charge the damage dice */
while (rand_int(10L * o_ptr->dd * o_ptr->ds) == 0) o_ptr->dd++;

/* Hack -- Lower the damage dice */
if (o_ptr->dd > 9) o_ptr->dd = 9;[/tt]

Note that this is within the hafted/polearm/sword ego-item (Very Good; power > 1) block.

Thus, upon creation of an ego-item, you will have a 1 in (10 * dice * sides) chance of an extra die or side, and re-calculate that if it's successful, and so on and so forth. For a 2d5 weapon, you'd have a 1 in 100 chance of that ego-item having better hit dice.

This can also happen for bolts, arrows, and shots.