Does Assassinate bypass Alert feat?

Question

My Mystic Monk was meditating when he was hit with an melee Assassination attempt by an Assassin. My Mystic Monk has the Alert feat which supposed "You can't be surprised while you are conscious. Other creatures don't gain advantage on attack rolls against you as a result of being hidden from you."

GM insists that his assassin automatically crits on my Mystic Monk without an attack roll. I get he does not get advantaged on any attacks from being hidden (which he was) from me, but doesn't he still have to attack me (roll to hit) to trigger the auto crit?

Answer 1

For reference, here is the Assassinate ability:

Assassinate. During its first turn, the assassin has advantage on attack rolls against any creature that hasn’t taken a turn. Any hit the assassin scores against a surprised creature is a critical hit.

So, the Assassin does, in fact, get advantage, since Alert only prevents advantage from being hidden, not advantage from not having acted yet.

But, since you can't be surprised, the Assassin doesn't automatically get critical hits on you. Even if they did, they'd still need to land a hit.

Answer 2

If we assume you are conscious while meditating, here are the rules in question with errata:

You can't be surprised while you are conscious. Other creatures don't gain advantage on attack rolls against you as a result of being unseen by you.

Then Assassinate:

During its first turn, the assassin has advantage on attack rolls against any creature that hasn’t taken a turn. Any hit the assassin scores against a surprised creature is a critical hit.

Reading this, the Assassin wants to engage in combat with you. Combat begins; you are not surprised. Everyone rolls initiative.

One might say "but why are you rolling initiative?"; it is simple. You aren't surprised and are in combat. You roll initiative. Normally a pure ambush would be an implied surprise, and they would start combat by making an attack then you roll initiative. But you are immune to surprise, so you get to roll initiative even when you have no warning that you are entering combat.

If you win initiative, you get to act first. You probably do not see the Assassin, so you do not act. The Assassin then attacks you.

The Assassin does not have advantage. The attack is not a critical hit unless it rolls it normally, because you are not surprised.

If you lose initiative, they get to act first. You probably do not see the Assassin. The Assassin attacks you.

The Assassin has advantage, as they are acting prior to you in the combat. The attack is not a critical hit unless it rolls it normally, because you are not surprised.

In no case does the Assassin auto-hit nor does the Assassin auto-crit.

Game fiction wise, you are so alert that even though you had no idea the Assassin was attacking you, as the attack was under way you actually started to dodge it. Your alertness is, basically, superhuman. It is opposed by the superhuman accuracy of the Assassin. Between the two, the Assassin gets a boost, but not nearly as large as against some other random target.

Answer 3

Your GM is wrong.

Assassinate. During its first turn, the assassin has advantage on attack rolls against any creature that hasn’t taken a turn. Any hit the assassin scores against a surprised creature is a critical hit.

Regardless of any other factor, there is no way the assassin can avoid an attack roll. The critical explicitly requires him to score a hit first.

The assassin does get advantage, because the first half of the ability is keyed to whether or not the target has taken a turn. If the assassin is first, nobody else has taken a turn. It's a question of initiative order.

The second half of the ability is keyed on scoring a hit and the target being surprised. If both aren't true, no easy crit occurs. It's a question of surprise, which is about Stealth and Perception checks. The Alert feat says the character cannot be surprised.