We reached silver level in our Road to Legend campaign.

"DOOM!" is a power card which adds one extra black die for each monster's attack. Does this black die upgrade on a silver die and later on a gold die when the campaign level upgrades? This card is pretty useless already even on Copper level...

How about Swarm ability? Kobolds get one extra black die for their attack for each monster surrouding the target. Is this ability better now? Are the dice silver or are they black even on gold level?

I am asking this because some of the heroes' skills upgrade when campaign level upgrades (ie. Parry).

Good question.

I would have thought so, given that the standard dice as marked on the cards go from black to silver to gold it would only make sense that the other cards increase the dice as the campain level increases, provided of course that you have paid for the upgrade for that creature type.

IE if you have upgraded beasts to silver, then extra dice from doom should be silver. but if your beasts are still at cooper then the doom card would provide only a black dice.

I dont have the rules here, but I would have thought that would be right, but descent has fooled me with its rules before.

AFAIK Doom stays the same throughout, but it's not as worthless as you suggest. +1 Black dice ~ +1/2 dmg per attack, and it increases the likelihood of surging out.

Kobolds can be killers with the Swarm ability, especially if you can spawn them round the corners. Remember it doesn't have to be Kobolds to increase the Swarm power. If you're concentrating your firepower on one hero - like any good OL should move the Kobolds in later on and you'll find they can be remarkably deadly. even if you fail to hit, you'll start raking in the Threat.

If your the Titan, properly upgraded Master Kobold will get bonus dice when they attack, RGoGoBlBlBl isn't bad. Then there's the opportunity to spawn Kobolds to block the party's progress... always a nice play to watch the party have to slog their way through half a dozen Kobolds to thwart their plans.

I tend not to bother with Doom, unless I have a load of threat and nothing to spend it on, I find it a fairly useless card in RTL, for what you pay for it. Can only have 2 power cards up at cooper, Trap Master is a must. (Spider Queen).

Extra OL card per turn (can't remember the name of the card) is nice if you can get it out early enough.

There is nothing in the rules (that I'm aware of) to suggest that the dice bonuses from Pre-RtL effects (like Doom and Swarm) upgrade with the campaign level. I do, however, take it as an implicit rule that these bonuses count as "dice upgrades" where applicable. ie: if your fully upgraded master kobolds already have 5 black dice for an attack, Doom will make one of those dice silver. Theoretically, by my way of thinking, if you had 2 Dooms out and a few monsters surrounding the target, a kobold could choose to upgrade a die to silver or gold without having 5 black dice first. Again, there's no support for this in RAW that I'm aware of, I just take it as implicit since these effects were written before the concept of upgrading dice colours was introduced.

I'm not saying that would make the effects any more powerful if you're already of the opinion it's not enough, I'm just saying that's how I play it.

I recommend all players read the FAQ. I recommend all players of RtL read it twice.

Q: When effects from “vanilla” Descent refer to black
dice, how do they relate to silver and gold power dice?
Does Doom! still add black dice at gold campaign level?
Can Trenloe the Strong and Lyssa reroll silver and gold
dice?
A: For Road to Legend, when an effect refers to a black
die, read it as referring to power dice in general. If an
effect adds a black die to a roll (such as Doom! or a power
potion), it instead adds one “boost” as if the subject had
spent one fatigue to enhance its attack. For example, a
copper level Master Beastman, which ordinarily rolls 1
black die, could roll either 2 black dice or 1 silver die with
Doom! in play. Lyssa and Trenloe the Strong may reroll
power dice of any color.

In addition to that, read the Swarm ability as defined in RtL - this answers the corresponding question as well.

Jake yet again said:

Not per the current FAQ, page 5:

Q: Under what circumstances can the overlord receive threat for rolling surges on an attack roll?
A: The overlord may spend two surges on each attack roll to gain one threat. He may do this on any attack that hits a hero. This represents a change from previous FAQ rulings on this subject.

You can still gain threat even if you don't penetrate the target's armor, but you have to at least hit a hero.