UPDATE after FAQ 1.1: The dice are great for investigators with an over-the-curve economy.

Pros

• The ability is not limited to skill tests, so you could also use it on cards where you normally wouldn't be allowed to react, like e.g. Final Rhapsody
• The reaction ability on Lucky Dice states "Ignore that chaos token". This drawn token is not returned to the chaos bag before "another one (is drawn and revealed) to resolve." This means that at least one token which would let you fail the test is out of the bag.
• As long as you have the credits to pay for the ability, you can repeat it infinite times. With one failure token leaving the bag with each investment, your chances of success rise, if you don't draw the -symbol. These dice can be a pricey life-saver!
• Decent install cost.

Cons

• The exceptional keyword: They cost 4 xp to include and are limited to 1 copy per deck.
• They take up an accessory slot.
• They only protect their wearer.
• There is a small risk of losing them for the rest of the scenario.
• Resource heavy ability: it costs 2 each time, you could also boost your stats instead to increase your chances of success, e.g. with Physical Training.
• Restriced use: If your chances to pass a test are very small initially, Lucky Dice are prohibitive. They only give you other tries to pass it until you run out of money.

As some confusion has evolved around the mode of operation, here comes the link to a in-depth discussion with answer from Matt Newman.

Contraband is a rather inefficient Rogue card. Its best use is certainly in multiplayer. If you can add 2 ammo to a Guardian's Shotgun, that's decent. It's hardly great, though, because you're spending 4 resources and an action to do it. In terms of actions and resources, that's almost as expensive as just playing a second Shotgun! If you play it after Extra Ammunition has been played, that's better, but now we're talking about a really slow and clunky multi-card combo.

Moreover, if you draw Contraband after the Shotgun has already seen some use, then it's useless. It doesn't do anything if your friend's Shotgun is out of charges, and it's pretty lame if it only has one charge left.

Contraband doesn't go well with any Rogue cards at the moment. Note that it does not combine well with Jenny's Twin .45s. Think of it this way: if you put 5 resources into Jenny's Twin .45s, and then play Contraband, you're not coming out ahead at all. You spent 9 resources and 2 actions to get an 10 ammo on Jenny's Twin .45s, when you could have just spent 10 resources and 1 action to accomplish that without Contraband. Once you initially put in 6 or more resources into Jenny's Twin .45s, then Contraband starts to generate a little bit of profit. But at that point, you just don't need that much ammo. For instance, you could spend 8 resources and an action to play Jenny's Twin .45s, and then 4 resources and another action to play Contraband. So that's 12 resources and 2 actions for 16 ammo. If you hadn't had Contraband, you could have just put your cash into the Twin .45s directly, which would be 12 resources and 1 action for 12 ammo. So you've effectively converted 1 action into 4 ammo. But that's not actually useful, because 16 ammo is just way more than you could possibly use.

So currently, none of the Rogue cards with charges are sufficiently useful or expensive that Contraband would make any sense. That makes this card multiplayer-only, and a rather questionable pick even then. But it is totally possible that we will see some new expensive cards in the future that justify the presence of Contraband, slow and expensive as it is.

Note that this card does not work with Shrivelling, which doesn't use ammo or supply tokens.

This might at first seem a card that's great in solo play but is not well suited to multiplayer. Now, it shines the brightest in solo play (duh), but I think it is excellent even at higher player counts.

Consider that this card does not need to activate every single round to generate a useful profit. Most scenarios last maybe 13-14 turns on average (some are a little longer, some a little shorter). If you drop this on turn 1 and manage to collect on it 60% of the time, you're getting 7-8 resources for the initial investment of 1 card, 1 resource, and 1 action. That's excellent.

And I'd say 60% is a conservative estimate. In most scenarios, there's enough space on the map that you can split up. Indeed, it is very often the correct strategy to do so. Furthermore, you only have to begin your turn alone. The flexible turn order of Arkham Horror really helps here. You can end your turn at the same location as your buddy, and then have your friend go first and move on to the next location. This is an easy way to collect Lone Wolf money while still teaming up with other investigators. My friend used this card as Rex in a 3-player runthrough of the Dunwich campaign; when he had it in play, I estimate he was collecting 80% of the time. If you can do anything near that, this card is excellent.

There are a handful of scenarios (in particular, The Gathering and Essex County Express) in which everyone is necessarily clustered together for most or all of the scenario. In these situations, Lone Wolf is indeed going to be pretty useless. In that case, just mulligan it out of your starting hand. If you draw it later, use it for the agility icon. (Adaptable may also be helpful here.)

Obviously, you need a plan for spending your massive pool of resources. I recommend the skill-boosting permanents (Keen Eye, Streetwise, Scrapper, Higher Education). These cards are already great, but Lone Wolf really takes them to the next level.

This card is quite bad. It might seem superficially attractive, as it's a skill card you can use to boost any important test, and then maybe get it back to boost another important test later.

The problem is the "succeed by 3 or more" requirement. This means that if you did well enough to get Opportunist back, Opportunist did not make a difference on the test. There are several Rogue cards that care if you succeed by 2 or more (Quick Thinking, Switchblade, .41 Derringer, etc.) but there are none except Opportunist that care if you succeed by 3 or more. So if you play Opportunist and succeed by 3+, then you get it back, but it didn't make any difference. If you succeed by less than 3, maybe it did make a difference, but then you lose Opportunist. See the problem? Even though it looks like you can use this card over and over, it actually can only help you a maximum of once per game, because once it makes a difference, it's discarded.

You might say that the point of Opportunist is that it won't be wasted if you happen to get a really good result, whereas something like Unexpected Courage would be. But in actuality, there are virtually zero tests where a) +1 makes a large difference to your odds of success and b) you nonetheless have decent odds of succeeding by 3+. The math just doesn't work out.

Moreover, there's always a chance that you fail the skill test (or succeed by 1, or succeed by 2 on a skill test that doesn't care how much you succeed by), in which case you lose Opportunist having gotten no benefit at all. Of course, every time you commit any skill card there's a chance it will be wasted. But other skill cards either do more to help you pass the test than Opportunist's rather measly +1, or grant a more useful reward for success.

Quick Thinking is a similar card that is much more useful. It has a better benefit--an extra action is better than just getting Opportunist back in your hand. (Consider that you could use that action to draw a card, or you could use it to fight, move, evade, or whatever's useful at the moment.) Quick Thinking can be used to boost other investigators, whereas Opportunist cannot. Finally, it has a lower activation threshold (2 instead of 3.) Unexpected Courage is a much-superior card, too.

Nonetheless, in the days when the Rogue card pool was thin, Opportunist would see some play, just because the wild icon was helpful. But with a recent influx of quality Rogue cards like Quick Thinking, Think on Your Feet, and Lone Wolf, Rogues no longer need to fill out their decks with chaff like this. Opportunist can be safely set aside.

The Exceptional keyword doubles the printed experience.

Do the investigator's deck building restrictions refer to printed XP or total XP cost?

For example, could Wendy Adams add this card to her deck, as she can only buy rogue cards costing up to 2 XP?