M1918 BAR is very strange weapon comparing other Firearm weapon. If you consider to use BAR, I recommand adding BAR-supporting cards.

BAR itself is not a good weapon. If you don't consider any supporting cards, you can easily find alternatives. I believe you don't use this weapon with spending 1 ammo(=1 damage) without anything. Then, you could trigger at most 4 times. Flamethrower has 4 ammos with 4 damage, and Lightning Gun has 3 ammos with 3 damage. If you want to find more continual weapon, .45 Thompson, Holy Spear, or Enchanted Blade exists.

However, BAR has high potential. BAR deals 5 damage with 1 action, which is the highest value among weapons. BAR has 8 default ammos, which is the largest among Firearm.

Supporting Cards

• Supplying Ammunition: Contraband, Swift Reload. Here, BAR has and spends lots of ammos. Thus, the card adding flat ammunition is bad. Sadly, both cards are cards. Note that Contraband can be played by another player, so that you may find your teammate with Double, Double.
• Extra Damage: Custom Ammunition, Enchant Weapon.
• "Eat lead!": As I know, ammos spent by Eat lead also contribute the BAR damage. However, I'm not sure and it's still issue. It means that you can evade without any ammo loss. Additionally, you can deal more than 5 damage with 100% succeed if ammo is enough.

8 16 32 64 128: 4 Contrabands make BAR as infinite 5 damage weapon. I heard that someone did it with Sefina by playing Contraband and doubled Scrounge multiple times.

Works incredibly well with Library Docent to switch from 1 go to location to another.

Daisy Walker can move a 4 player team to the locus in 1 turn.

No attacks of opportunity means lecturing stuff to monsters. Engaged monsters move with you. Hello helpy guardian friend, I brought a monster with me.

This is a spicy little card. Actions are how you win the game, and getting an extra 6 actions (before you get into secret shenanigans) over the course of a scenario is a big deal. 2 resources to buy more of the most precious resource in Arkham, Time, is quite the trade.

As a bonus, these are actions you often want to be taking. Moving is a necessary tax in most scenarios and being able to do it free massively ups your efficiency, Investigate is how you win the game and are the Seeker's main job, and Evasion can be empowered to be an extremely efficient action for rogues that can amp this up to being worth 9 actions a game with just one copy of pickpocketing 2 alone!

I think Seekers will want this more, simply because move-investigate is going to nearly always be amazing for seekers while move-evade is more situational (though it is a nice thing to pair with lockpicks, many lockpickers are apparently serial smokers), many seekers don't have great a ton of options for their accessory slots, and because seekers can more easily replenish the secrets with cards like Astounding Revelation.

The main thing this is in competition with is Pendant of the Queen but the anti-synergy here is actually really mild, and despite sharing a slot the cards actually work quite well together: Both reward you for running astounding revelation, due to the Pendant rewarding deck search and the chart rewarding secret recharge. Both are temporary assets giving you extreme mobility and action efficiency. And it generally takes a bit, even with good deck search, to get a Pendant going, so you can run an Eon Chart early, use it up in time for Pendant to come out, and then if you run out of your Pendant go back into Eon again to help close out the game!

This card is interesting thematically because, while Rogues have a lot of betting in their thematics, they tend to NOT gamble! A rogue, before this card, said "Gambling is for chumps" like the ace hustlers they were and what their cards were more about them being certain about the outcome and deciding to make calculated wagers, not gambles. They leave that for Mystics and Survivors!

It isn't going to affect the mechanics one way or the other, but it does make my rundown of Rogues for new players a bit less accurate!

"Highlander" decks in most games are interesting, because you are ending up with far more variance in exchange for some benefit.

This is an especially interesting highlander card because it is paying you off for rolling highlander... with consistency?

Lets take an opening hand mulligain, assuming a 33 vs 28 card deck with 2 weaknesses and 1 signature, where we ignore the weaknesses and are just trying to hit one, super specific card at all costs.

In a standard deck, if you 'hard mulligain' for the card, you have about a 54% chance of finding at least one copy.

In an Underworld Support deck, you only have a 35% chance of getting that copy.

This means this card isn't great for increasing your odds of getting your one specific card 'by default.' Deck thinning turns out to be fake, yet again...

OR IS IT?

Lets look for situations where it works better! Because this is not an unsalvageable situation

Firstly, there is the case where you have alternatives that are viable. Weapons are a great example. If your deck is normally running two copies of a weapon (As some of you psychos are!) and running Prepare For the Worst, and you happen to get the tutor rather than the weapon early, you have an 50% chance to find one copy in your 9 card search right away, and a 70% chance if you wait 3 turns (and draw 3 cards) before searching to see it in draws and searches, normally. But if you run both Prepare and Prepare with Health, and two DIFFERENT weapons, you have an 65% chance to find it right away, and an 80% chance to draw it 3 turns later.

Some pretty meaningful improvements, if not drawing your weapon in that scenario screws you, you will be salvaging 1 in 10 games that way, roughly. But you will notice the effect is more pronounced if you do it earlier. So as long as you can do this for most of the tools in your deck and bypass the highlander rule, you can get noticeably more consistent both draw to draw and for searches or other bulk draw scenarios.

Deck thinning is only fake if the cost is not worth the consistency, or if you are doing something dramatic and silly to get rid of the cards. In reality, deck thinning is VERY real (every card drawn is deck thinning after all), the question is 'does only running singletons of my cards noticeably make my deck worse more than it helps? It is going to be up to how dramatic the cost of running highlander really is in your classes. Mystic and Guardian Rogues have a lot of redundancy in their best tools, while a rogue hybrid (or anyone with access to level 0 rogue cards!) who have more specialized cards, like Survivors, may struggle to find alternatives for everything. It also limits more niche strategies: Sure guardians have a lot of weapons, but if you are going something more narrow like bless synergy it is harder to find replacements.

And, oh hey... wait a minute... isn't there a Rogue Mystic who doesn't mind having a diverse set of abilities because she can recursively play them as long as she can consistently get them into their opening hand, and who would love to more consistently nab one of her 3 copies of her signature?

Sefina goes from an effectively 38 card deck, down to a 36 card for the purposes of her opening hand. This means, despite her upshot of drawing 13 cards in her opener, her chance of seeing any specific cards she took two of is only 60%. But a lot of her staple tools have viable alternatives. Sure, everyone loves Shrivelling but would it really be such a nightmare to run armageddon in a non-curse deck if it let you ensure you open with a 'weapon' almost 20% more often? And that is just the really bad replacement! Sixth Sense and Rite of Seeking are downright fairly competitive with each other, and there are plenty of fantastic rogue and mystic event cards to populate your deck with to ensure you can cast your bag of tricks.

Sefina is probably most likely candidate for this card for that reason, though it isn't impossible for others to find value from it if they have enough fantastic options, and at the same time I am not holding my breath for this to be a "Sefina Standard" either.

The most 'valuable' aspect of this card though, is to do what Highlander as a format in MTG was originally intended to do: Force you to use more creative decks and explore more of your collection. While it is possible to really math out the benefits and say "Oh wow, a 14% higher chance to get the card I want in X situation" it is always going to be questionable if the increase in getting A tool for the job is better than always getting THE tool for the job.

The real value in this card, and why I suspect it will be popular no matter how good or bad it is, is that it is almost a voluntary taboo that forces you to really evaluate every funky 'offbrand X' in your collection, with juuuust enough reward behind it to make it a pleasant experience... and, maybe, just maybe, if you are a really clever deck builder, a card that can actually give you an advantage.