This card seems like it needs other cards in order to work well. Here's a list of cards that it appears designed to integrate with:

• Sleight of Hand
• Narrow Escape
• "Eat lead!"

This is a weapon you definitely only want to play when you really need it. Narrow Escape is nice, because you can wait until an enemy shows up, play this card, then use Narrow Escape to get +2 to the first attack. Sleight of Hand is nice to make this weapon fast and to make it last for more than 1 turn. Out-of-class, "Eat lead!" is the only way available to use all of that ammunition short of some serious shenanigans.

A lot of cards have anti-synergy with this weapon. It should go without saying that Custom Ammunition, Extra Ammunition, and Venturer shouldn't be used for it. It's just a waste!

The card's nearest in-faction comparison is the .41 Derringer. Do you want a good gun for one turn, or an okay gun that will last you for 3 shots? Overall, I think you might get slightly more mileage out of the .41 Derringer. However, the Colt Vest Pocket does have its uses. It's not a long-term combat solution, and you need cards to support it, but it can do some damage in a pinch.

I haven't had a chance to use this card yet, and generally higher-level events are a smaller priority for me in deckbuilding since I tend to focus experience points on assets.

However, I can see people using this card as "Brother Xavier's Parting Gift" - you can play this card and take 3 damage on Brother Xavier for a potential 6 damage on an enemy. That's a powerful attack.

Still, it's something that requires 4 experience, 6 resources, and a few turns of setup in order to do. Is it worth it? Maybe in some situations, but I think usually experience is better invested elsewhere.

Although 3 experience is pretty steep for a one-off attack, there are a couple investigators for whom this haymaker plugs a gap.

Carolyn Fern has lots of conditional ways to deal with enemies; her Mind over Matter is best with an otherwise-underwhelming Machete, Shrivelling needs several boosts to be reliable, "I've got a plan!" requires setup, Dynamite Blast is expensive, and Guard Dog or Beat Cop take the ally slot that she would prefer to be Peter Sylvestre. This ranks highly in that company, the self-damage being analogous to dynamite and it can be soaked or healed by usual tricks.

Likewise Marie Lambeau might find this a reasonable addition to her spell arsenal, especially since the damage can off a David Renfield to a doom-free grave.

Its worth pointing out that Leo Anderson has 4 and can take damage with low risk, but he has so many options for dealing with Poltergeist that he can safely ignore it.

Fun fact - did you know this was the first card with the Permanent keyword that wasn't an asset? It's kind of weird when you consider that cards like the John Dee translation of the The Necronomicon are considered assets. Most other Permanent cards are assets, so it makes it a bit unusual in that regard.

Looking at the rules as written - seen here - could suggest that this card actually has no effect since it's classified as a treachery and not an asset. "When a treachery card is drawn by an investigator, that investigator must resolve its effects. Then, place the card in its discard pile unless otherwise instructed by the ability." You technically never draw it, so you never trigger the effect, right? I could see someone reading these rules and interpreting the card this way. However, I think it's pretty clear that's not how this card is meant to be interpreted.

A more devastating read of this card would be "you start each game with 2 fewer resources" reading that each game starts you with 2 resources less than the game before it, so that your progression could look like this:

• Game 1: 3 resources
• Game 2: 1 resource
• Game 3+: 0 resources

Technically the wording is ambiguous enough that you can read it that way. Tough, right? Again, I don't think this is how the card was meant to be interpreted, but it could be read that way. (But it shouldn't be, because I am very sure it's just a flat -2 resources at the start of play.)

As for my actual thoughts on the card, I generally find it to be one of the more preferable weaknesses. It's one of the weaknesses that actually impacts my playing more, actually - with less weakness cards in the deck, I am more likely to draw more. The downside is that it does get you with its effect every game, but I believe that one of the keys to a good deck is consistency, so I like knowing exactly when a weakness is going to hit. It's something that you can take into account for your plan. It does slow your start a little bit, but it saves you that tempo hit later on in the scenario. Having 3 resources still gives you enough to play key cards like Machete and Shrivelling (and Dark Horse, of course!) to get you started. Is it possible that 2 resources could be the difference between winning and losing? Yes, but most of the time this is just a minor and predictable setback. I still think it's well balanced, though - annoying, but not completely negligible.

How does this work? It has 5 ammo. You spend one action and one ammo to fight. How is one meant to use up all 5 ammo in one round? I can think of Gold Pocket Watch or Ace in the Hole, but I am not a fan of cards needing other cards just to be serviceable.