In the mythos phases where this is good, I foresee it being amazing. Sometimes you'll get three draws that your seeker/mystic could easily handle and will just have to make do, but if there is a round where your seeker cannot be bogged down with enemies because they need all their actions to win the scenario, this is insane. Give yourself all the enemies (are you roland or Zoey?), avoid all the horror (have fun, agnes), and give your allies the breathing room they need to win. Much like ward of protection, I think this will go in every deck that can take it as a safety against defeat late in the scenario.
Fast. Play when the "draw encounter cards" step of the mythos phase would begin.
Instead of resolving that step, look at the top X cards of the encounter deck, where X is the number of investigators. Deal those cards among the investigators as you wish, dealing no more than 1 card to each investigator other than yourself. Then, one at a time, each investigator draws the card(s) dealt to them.
There's a very interesting mathematical analysis around this card in my opinion. At first I considered each combination of possible card splits as all the possibilities this card allows you, but then I noticed that each investigator draws the cards dealt to them one at a time (presumably in mythos phase order), which means you technically also get to choose the order you draw all the cards you deal to yourself. This makes the possibilities explode even further. In other words, the order of the cards matters, and without loss of generality all we have to do is combine all the possible orders of the cards with all the possible choices of who can be assigned cards:
- One investigator. (A). 1 possibility
- Two investigators. (AB, ) or (A, B). 2 orders x 2 assignments = 4 possibilities.
- Three investigators. (ABC, , ) or (AB, C, ) (x2, one for each person) or (A, B, C). 6 orders x 4 assignments = 24 possibilities.
- Four investigators. (ABCD, , , ) or (ABC, D, , ) (x3, one for each person) or (AB, C, D, ) (x3, one for each pair) or (A, B, C, D). 24 orders x 8 assignments = 192 possibilities.
The math is obviously less impressive if you don't particularly care about the order that you draw the treacheries, but it's still really good:
- One investigators. 1 possibility.
- Two investigators. 3 possibilities. (Goes from 2, 2 to 1, 2).
- Three investigators. 13 possibilities. (Goes from 6, 12, 6 to 1, 6, 6).
- Four investigators. 73 possibilities. (Goes from 24, 72, 72, 24 to 1, 12, 36, 24).
Either way you choose to look at it, this card explodes the possibility space at higher counts. The only caveat I'd make with the math here is that it doesn't account for duplicate treacheries which will heavily cut down your options. Even still, at 4 players or even 3 players I think you need to have a very strong reason to not take this card. The main killer in this game is tempo, whether that's not having enough time to do everything before doom runs out, or not having enough actions to deal with all the threats before you become defeated. First Watch, for a ridiculously low cost, can buy you an entire Mythos phase worth of tempo. Daisy won't care about that Rotting Remains, give it to her; let's have Mark draw the ghoul so he can kill it in one shot; let Diana cancel that Frozen in Fear no one wants to deal with, you get the jist.
Who should take it? Anyone with access at 4 players, full stop. I think the card is really that good. Do you like The Gold Pocket Watch? This is kind of like a non-exceptional mini version of that. At 3 it's a bit hazier but still amazing, and I think it's worth making sure you include a copy or two. At any counts below that the card is basically useless and not worth running at all.
If you want some particular investigators:
- Diana Stanley can throw something to cancel onto her.
- Zoey Samaras and Leo Anderson have great statlines to stand up to the encounter deck.
- Mark Harrigan and William Yorick love having more enemies to fight.
- Tony Morgan can use it to throw tests at his friends while taking out a few bounties for himself.
EDIT: A new little exploit has come to light. First Watch replaces your entire Mythos phase. Say in a 4 player game you have 3-1 cards left in the Encounter deck, you only draw those cards and distribute them among 4 players, and that's your entire Mythos phase. So if there were a single card left, and you played First Watch, you effectively cancelled 3 treacheries. Now it's questionable how often you'd be able to do this: it depends on how many non surge cards you have in an encounter deck and whether that number is divisible by 4, plus some effects may mess with the numbers in other ways (eg Stargazing), not to mention scenarios where you get consistent reshuffles of the discard pile. But, if you can pull it off, it's a hell of a play.
Getting the obvious out of the way; solid card in multiplayer, useless in single-player, cheap event that you'll always be able to play and rarely have a reason not to.
Now, with that said, I wish to talk about one very specific situation involving this card; the event you decide "screw it!" and subject yourself to four encounter cards in one phase. This will be a highlight of any game session, and I recommend trying it just for that reason, even if you perish in a hilarious fashion by your own hubris. In the spirit of trying to survive this self-imposed nightmare, here are three investigators who are most likely to pull it off:
1) Zoey Samaras
High ? Check. Benefits from drawing enemies? Check. Needs few cards to come online? Check. Zoey ties with Leo Anderson for highest among the Guardians, but Leo needs a few more cards out before he's ready to endure the encounter deck, and his 1 makes him slightly more vulnerable to the second most common skill test printed on encounter cards.
Most if not all Dianas will be running encouter hate, meaning that the're often disappointed when they couldn't cancel an effect because someone else drew it. No more! With the highest potential base and decent , she will be able to handle most tests that come here way. Her balanced health/sanity thresholds and access to guardian cards top off her status as most likely mystic to handle an encounter tsunami.
3) Jenny Barnes
Jenny might seem like a dubious choice to take on the mythos, but several rogue cards exist that help to this effect. Her decent and stats can be bolstered with Well Connected, or replaced with Money Talks, two cards that Jennys are already inclined to take. Tennessee Sour Mash helps both with checks AND enemies, Cunning with checks, and Jenny's Twin .45s with enemies too.