BUG: Power Drain in item has no effect

[I like Serena]

Bug description
When an item has the Power Drain power, it is supposed to siphon off 2-20 mana from the target hero or creature.
However, neither a staff of Power Drain, nor a power-draining sword drains any mana.
Not from a hero, not from an efreet, nor from a shaman.

Versions
This bug is present both in vanilla 1.31 and in insecticide 1.40n.

Confirmation
RJAK confirmed the bug on the wikia.
See this page in the comments of the section "Colors of Ranged Magic and Special Attacks".

Save game & Reproduction
Here's a save game.
Zaldron has a staff of Power Drain and also magic immunity to prevent him from getting killed.
He can reach a hero and an efreet in his turn.
One complication: the enemies spend all of their mana in the first turn.
I used the Tweaker to give them some mana back.

Code analysis
While searching in the code, I can see that the Power Drain power is registered as an attack flag, but it does not appear to be handled anywhere.

[Anthony]

As a side note, the tendency of the AI to immediately burn all its mana also renders power drain not very useful. The easiest fix is to probably just remove the effect. A version that would be useful might do something like cast Dispel Magic every time it hit.

[I like Serena]

As a side note, the tendency of the AI to immediately burn all its mana also renders power drain not very useful. The easiest fix is to probably just remove the effect. A version that would be useful might do something like cast Dispel Magic every time it hit.

Perhaps not useful for you, but how will it make you feel if an enemy starts syphoning off your mana?
Anyway, I don't consider removing features, or crippling broken effects for that matter, a good fix.
What I would like for Insecticide is for missing or crippled features to start working, so they can enrich the game in ways that are as yet unforeseen and mysterious.
Of course the feature might have a different effect in a mod.

[kyrub]

Funny, I never heard about Power Drain capacity; or never noticed such a feature existed, to be precise.
Impressed by your structured info, ILSe. This should be corrected, all the tools are there. -- My debt with Insecticide is worryingly growing. A lot can be done in 1.40o.

"The item should siphon" -- does it mean should siphon when hitting the enemy? Or siphon every turn, as with mana drain spell?

[I like Serena]

Funny, I never heard about Power Drain capacity; or never noticed such a feature existed, to be precise.
Impressed by your structured info, ILSe. This should be corrected, all the tools are there. -- My debt with Insecticide is worryingly growing. A lot can be done in 1.40o.

Thanks. I was surprised that apparently nobody noticed before that it did not work.
Not even B0rsuk who used to find bugs at a prolific rate.

"The item should siphon" -- does it mean should siphon when hitting the enemy? Or siphon every turn, as with mana drain spell?

The only information I can find in the game manual, the spell manual, the strategy guide, and the game is:

Game Manual - Table M: Power Drain, 3 Death books, All weapons, Not on armor or jewelry, Opponent wizard loses 2 to 20 mana.
Game help - on item: Power Drain, target loses 2-20 mana.


The fact that it is on a weapon and that it is an attack flag implies that it should only work when hitting or shooting an enemy that has mana.
Since no resistance roll is mentioned, I interpret that as no resistance roll being applicable.

The wikia has a fairly extensive page here, but basically it says the same thing.

[robinh3123]

Funny, I never heard about Power Drain capacity; or never noticed such a feature existed, to be precise.
Impressed by your structured info, ILSe. This should be corrected, all the tools are there. -- My debt with Insecticide is worryingly growing. A lot can be done in 1.40o.

"The item should siphon" -- does it mean should siphon when hitting the enemy? Or siphon every turn, as with mana drain spell?

Power drain exist only in weapons. Black wizard can make such weapon via create artifact. Those weapon can also be obtained from merchants.

[FrancoK]

Thanks. I was surprised that apparently nobody noticed before that it did not work.

I'm surprised, too. I thought it did not work, but I never reported it. Like Merging.
Good job. :ok:

Reading the info, the "target" will lose mana points, no saving.
Since a unit cannot target the enemy wizard, only another unit (with mana points) can be drained.
As a mod, the drained mana can be siphoned to the attacker (or its wizard), but not in the standard patch.