when investigator in the same place engaged multiple monsters A, B

first. When an investigator attacks Monster A, does A monster counter to me, and B monster does not attack the investigator?

second. If my question is correct, in the same situation, if an investigator attacks Monster A, and Monster A receives damage to die, does A end its fighting without countering the investigator?

I will try to answer this as best I can.

1a. You are engaged to 2 monsters (A & B). You attack A, which does not have Retaliate and either: hit, dealing your damage to it, or miss, no effect. Or you attack A, which does have Retaliate, and either: hit, dealing your damage to it, or miss, and take damage from the monster. Monster B, does nothing in any of these instances until the enemy phase.

1b. You are engaged to 2 monsters (A & B). Another investigator attacks A, which does not have retaliate, and either: hit, dealing their damage to the monster, or miss, dealing their damage to you. Or another investigator attacks A, which does have Retaliate, and either: hit, dealing their damage to it, or miss, dealing their damage to you and monster A deals its damage to you. Again, in all instances, monster B does nothing until the enemy phase.

2. If you, or another investigator, deals enough damage to monster A to kill it, then the monster dies and deals no damage to you (or the other investigator). Monster B does nothing until the enemy phase.

I think you may have the basic sequence down wrong.

3 hours ago, Kazasaky said:

first. When an investigator attacks Monster A, does A monster counter to me, and B monster does not attack the investigator?

No, neither monster will attack you. Counter is really not a word/concept in the game.

3 hours ago, Kazasaky said:

second. If my question is correct, in the same situation, if an investigator attacks Monster A, and Monster A receives damage to die, does A end its fighting without countering the investigator?

Again, no attack/counter.

To sum up the sequence if you are engaged with two enemies:

1. If you take any action other than Fight, Evade, Parley or Resign, both enemies will perform an AOO against you.

2. If you take any of those 4 actions, neither enemy will perform an AOO. You attack and the monster doesn't attack.

3. During the enemy phase, if any of those monsters are unexhasuted and engaged with you, they will attack you.

4. If an enemy has the retaliate keyword on it and you attack it and fail, the monster attacks you.

i didn`t know about retaliate. thanks you all, and i have more question

1.when investigator already play ally (ex. Dr Milan Christopher in play )
2. investigator want in hand to play area to 'guard dog'
3. investigator engaged 2 monster.
4. when use asset card play area from hand, engaged monster attacked investigator, right?
5. then, investigator gain minimum 2 damage (engaged each 2 monster can AOO 1 damage ) , investigator Assign 1 damage to Dr Milan Christopher? ( when investigator use asset card > monster AOO to investigator > ally not yet replaced damage assign > change guard dog .
can i this action?

10 hours ago, Jobu said:

I think you may have the basic sequence down wrong.

No, neither monster will attack you. Counter is really not a word/concept in the game.

Again, no attack/counter.

To sum up the sequence if you are engaged with two enemies:

1. If you take any action other than Fight, Evade, Parley or Resign, both enemies will perform an AOO against you.

2. If you take any of those 4 actions, neither enemy will perform an AOO. You attack and the monster doesn't attack.

3. During the enemy phase, if any of those monsters are unexhasuted and engaged with you, they will attack you.

4. If an enemy has the retaliate keyword on it and you attack it and fail, the monster attacks you.

question about 3.

not engaged hunter monster in investigators area beside area.

in enemy phase, hunter monster move investigator area, then hunter monster hit investigator?

53 minutes ago, Kazasaky said:

i didn`t know about retaliate. thanks you all, and i have more question

1.when investigator already play ally (ex. Dr Milan Christopher in play )
2. investigator want in hand to play area to 'guard dog'
3. investigator engaged 2 monster.
4. when use asset card play area from hand, engaged monster attacked investigator, right?
5. then, investigator gain minimum 2 damage (engaged each 2 monster can AOO 1 damage ) , investigator Assign 1 damage to Dr Milan Christopher? ( when investigator use asset card > monster AOO to investigator > ally not yet replaced damage assign > change guard dog .
can i this action?

You have to resolve everything including AOO before the card goes into play. So it can hit Dr Milan he dies since he just has one life. The other point goes to you or some other asset in play. Then the Guard Dog enters play.

36 minutes ago, Kazasaky said:

question about 3.

not engaged hunter monster in investigators area beside area.

in enemy phase, hunter monster move investigator area, then hunter monster hit investigator?

Yeah, Hunter moves into space with the investigator, immediately engages the investigator. Then they attack the investigator.

1 minute ago, Jobu said:

You have to resolve everything including AOO before the card goes into play. So it can hit Dr Milan he dies since he just has one life. The other point goes to you or some other asset in play. Then the Guard Dog enters play.

Yeah, Hunter moves into space with the investigator, immediately engages the investigator. Then they attack the investigator.

got it. thank you very much

3 hours ago, Kazasaky said:

5. then, investigator gain minimum 2 damage (engaged each 2 monster can AOO 1 damage )

Attacks of Opportunity deal full physical damage and mental horror, not just 1. It's possible the particular enemy deals only 1 damage, but you could ending up taking 2/2 from an AoO.