Some interesting or high-value Tactic events I came across:

• First Watch: Such a good card. To play it each round is bonkers.

• Counterpunch: This is one of the no-brainers and probably the intended use of the Book. Don't waste precious actions on enemies, just play this.

• Ambush: Before grabbing enemies via "Where's the party?" or Kicking the Hornet's Nest during your turn.

• Dynamite Blast: If you have enough resources, this could be strong.

• Barricade: For sticky situations where you want to get rid of engaged enemies or some effect causes enemies to move during the investigation phase. Basically just to circumvent the forced effect.

• Hiding Spot: Since this card has no play instructions you can play it during ANY player window and your whole group benefits from its effects during the complete investigation phase. Next turn, repeat.

• Hit and Run: I am sure with a bit of theorycrafting you will find sweet combos via recurring this. Dunno, maybe Charlie Kane with Summoned Hound or The Red-Gloved Man? Or tarot plays with Anna Kaslow? Or Library Docent to replace your empty Book (if you have another Tome in your hand).

• In the Shadows: As long as you don't have to kill enemies it's great to be invisible all the time without having to rely on crazy deck-cycling builds. Additionally, Trish Scarborough actually has great access to secret replenishment to get even more out of the Book. Needs Versatile, though.

• On the Lam: My personal favorite. I built a whole deck around playing it each turn and eventually blasting the horde you gathered via "Where's the party?" and Kicking the Hornet's Nest with Dynamite Blast and Stir the Pot

• Additionally, you can combo the Book with Crystallizer of Dreams, which feels wow :)

There is Making Preparations, but Dilemmas are not played, so this doesn't work (also for this card, it wouldn't make sense to recur it).

It's funny that a lot of Tactics let you either avoid enemies or rough them up real good. Then again, it's sort of in the name.

I have re-checked the erratum on Wendy's Amulet but I don't think it prevents the below interaction to work.

In a 2+ game, give it to your main fighter in addition to On the Hunt: during the mythos play On the hunt, spawn the enemy, use The book of war, defeat the enemy, get your resources, and at the end of your turn get On the hunt back.
Replay each time you need an enemy (for Parley effects, Under Surveillance, Ambush, ...)

In a Zoey Samaras deck you can even kill the enemy when you engage it thanks to the Zoey's Cross. Especially interesting for Aloof or Cultist enemies: Acolyte, Whippoorwill, ...

P.S: if this combo doesn't work due to the fact that On the Hunt is not discarded right away, there is the inferior combo with On the Hunt / Kicking the Hornet's Nest (you need to find an enemy among the first 9 cards of the encounter deck.

How does this work with Winging It and Improvised Weapon when you play those Events from the discard pile? The texts conflict with each other.

If this works with those abilities, Marion loves this even more.

This is a 0 exp card? Really?

The book is pretty much game breaking given the power level of tactic cards. The simplest and most broken usage is replaying First Watch 4 times, which kills the game regardless of the difficulty because, to be fair, more than half of the game challenge comes from randomly drawing encounter cards. With the help of Stick to the Plan, you will only need to find this book in your mulligan to shield your team from unwanted encounters for 4 turns. Not only that, your can add Ever Vigilant to save your team actions of playing assets at the beginning of the game. 4 assets are not enough? Sure, do another rounds to play 8. You'll feel pretty much no blocker in the scenario after all these, unless your team has disastrous deck building or team composition.

What do you need to achieve these? 6 exp for Stick to the Plan, easily achievable after scenario 1 with In the Thick of It and Delve Too Deep; 4 exp for Ever Vigilant, after scenario 2. All you need to do then is drawing 5 at the beginning of the game, no The Book of War? Mulligan all 5!

Carson will be an ideal executor of this as team support, because he can take seeker cards to draw for the book if it does not show up in start hand and recharge it using Truth from Fiction.

Some additional thoughts on tactic cards

We know that guardians are usually restricted by draw power and resource gaining, though a lot of guardian cards are pretty powerful, like they ones I mentioned and those other comments mentioned. Typically guardians have difficulty drawing these cards in a consistent way at the beginning with the game, unless it's a tactic and you have stick to the plan, or even if you do, you need to draw through your entire deck to play those powerful cards again, which is not what most guardians are good at.

Now with this book, that is not a problem. You can put powerful tactic cards under stick to the plan to access them consistently, then search for this book to play those cards every turn, up to 4 times before a reshuffle. This does not seem right to me based on the power level of those tactic cards, because they were designed when guardians can play them only once in each reshuffle.

This card is a guaranteed nerf to me, to 3-4 exp, or even made exceptional or removed from game after you exhaust all secrets (even that will not truly stop it because we can easily recharge it with Enraptured and Truth from Fiction).