The Hidden Blade Assassin's Creed in Depth

Didn't stabguy do a video where he carried him to the water? and threw him off the edge? I know it's not a roof... then again, maybe he was already dead in that video...

You mean this one: http://www.thehiddenblade.com/taking-out-trash-uberto-alberti
He's already dead in that video.

I have a plan though:
I want to civ-throw-bump Uberto to the docks with stairs (to clear your mind: it's where Ezio brings the bodies of his father and brothers in ACB, I think), but instead of taking the stairs, bump him over the ledge above. He won't fall in the water that way, but onto the stone docks.
I hope I've explained it clear enough. Anyway, let me know if there's something I've overlooked or if you have any ideas.

Will he follow you up a ladder? Or once he's detected you do you auto-fail? I don't remember.

Once you get close enough (from every approach, so no sneaking up behind him), he will face you and start talking. When you get close enough for an assassination you will be prompted to press which will start a cutscene of Ezio repeatedly stabbing him. When has seen you and finishes his talk, he will call for guards and you will be detected (detection=mission failed).

so the plan is to kill all guards within earshot. if there are no guards to call, are you still detected by him at the end of his speech?

You can pre-kill all the guards on the ground, including the two brutes at one of the entrances. The ones up on the roof will re-spawn but the ground ones won't. If this helps.

ETA: I vote for "leap of fail".

ETA again: I don't think there are any ladders in the immediate vicinity - just boxes to climb up. So you'd have to do the grab-and-throw civilian for probably quite a distance to even see if he will climb one. Good luck with that!

Right now, I think, right from my head, the major problems will be Urberto and Rodrigo Borgia.

As soon you come close to him, the cutscene starts, so is hard to make him get to a higher ground.

And, as we know, we fight Rodrigo in a place with no drops.(The Church in Rome)

So I think you should included "drop on water way of kill" as part of the challenge, so you can do a Early Kill on him at Venezia.

I think this will be necessary for Emilio too.

Emilio is actually really doable. He'll walk up to the upper balcony eventually.

As for Uberto, that's a toughie. Gerund's approach looks the most promising to me, but once you actually get in there and try it you think of a bunch of other stuff to do.
There are some really easy targets like Vieri and Antonio Maffei, but on the whole this is going to be really tough. I might try running it a bit on stream, looks like a fun challenge.

Well, I really don't know if the height of the balcony in the Palazzo is enough to kill him on the fall.

I fact, I don't know what height is considerated lethal to a NPC, so I am speculating, at best.

You guys seem to have forgotten my video.
http://thehiddenblade.com/uberto-alberti-non-story-assassination

That doesn't count as an assassination, but I'd think it'd be bad not to include it. I think we should set up a scoring system regarding this challenge to work around this. Here's my proposal:

10 points for a Leap of Fail: the target dies from fall damage, without taking any damage whatsoever beforehand. After the target is dead, the story proceeds as normal.
8 points for a Slip 'n' Trip: the target dies from fall damage, having taken damage from just falls beforehand. After the target is dead, the story proceeds as normal.
6 points for a Deliberate Accident: the target dies from fall damage, having taken damage from something else than a fall beforehand. After the target is dead, the story proceeds as normal.
2 points for a Swimming Lesson: the target dies from getting in contact with water. After the target is dead, the story proceeds as normal.
6 points for a Non-story Leap of Fail: the target dies from fall damage, without taking any damage whatsoever beforehand. After the target is dead, the story does not proceed. (we call this a 'softlock')
4 points for a Non-story Slip 'n' Trip: the target dies from fall damage, having taken damage from falls beforehand. After the target is dead, the story does not proceed.
3 points for a Non-story Deliberate Accident: the target dies from fall damage, having taken damage from something else than a fall beforehand. After the target is dead, the story proceeds as normal.
1 point for a Non-story Swimming Lesson: the target dies from getting in contact with water. After the target is dead, the story does not proceed.

The reason I gave Swimming Lessons so little points is that they are very easy to set up, especially if they're non-story. Critique is very welcome. Also, should we allow resets? I mean they're kinda mandatory for non-story assassinations, but what if you can do a Leap of Fail, and then find a way to do a Slip 'n' Trip as well? Personally I'd say only one special assassination per target since if you find a way to do a Leap of Fail, you can also easily setup a Deliberate Accident by just punching the target once, so a LoF would be worth 16 points effectively.

Ab-so-lutely not!! When I accepted this challenge I started looking for Uberto videos on this forum, and your video inspired my approach! I'm sorry for not giving you credit for that.

I am going for a 100% completation right now, but soon I finish, I think I will start a new game and try to take this challenge.

Looks so fun! Do you guys always has this kinds of challenges? XP

There are a few going on, generally. There are speed runs, of course - Fed981 specializes in them and Phi is working on an AC1 one at the moment. There are minimum kill ones, where you eliminate the targets only (plus the ones you can't avoid, like in a tutorial). Gerund recently did an AC3 run where he got the lowest synch percentage he could manage.

This one is new and it does look extremely fun and creative.

Don't forget the open ended challenge for ACB that still hasn't been achieved (to my knowledge) ... http://thehiddenblade.com/i-will-bring-each-citizen-safety-challenge

Can someone explain the mechanics of detection in the Uberto assassination?

I used thieves to lure away two guards, who were guarding one of the entrances to the cloister. I chased them to assassinate both, and out of nowhere (the distance meter showed 71!!) the all-seeing eye of Il Gonfaloniere spots me;
1. Civilians start looking at you and start moving away.
2. Uberto starts talking to you: "You..." "Guards, arrest him!" "Abbattetello."
3. A message appears at the bottom of the screen: "Assassinate Uberto."
4. The other guard that was lured away, whom I was chasing, could have turned towards me when I killed his buddy, but HE DIDN'T!
5. After Uberto says "Abbattetello", that's when you get detected and auto-fail. That's when the guards turn towards me.

Point 4 and 5 indicate that there's a difference between guard-detection and Uberto-detection. I have no clue what does and what doesn't trigger Uberto-detection.

--

One thing that triggers Uberto-detection is EZIO killing a mission-specific guard (the ones guarding the entrances or roof). So in order to clear the area (and yes, it needs to be cleared in order to get him where I want him) I need to use mercenaries. Problem is, I can only find some thieves and courtesanes. Does anyone know a place where mercenaries are?
btw, I've found a good spot where I intend to drop him, the only question is whether it's high enough to kill him.

Well, sense I am playing the games right now in order, when I reach ACB I will try that, looks challenging do with without Allies.

@Gerund

Before testing the Drop Spot on him, use a Guard or citizen as test subject, drop one of them from there, and see if he bounce! =P

Okay, I'm totally losing my head over the Uberto assassination, so I'm postponing it. I tried to throw civilians over the ledge I had in mind, but it didn't kill them. If I could just throw Uberto over that ledge, that's enough for me, personally. Even if he doesn't die. You can't have everything, right? Also, in order to get him there I need the whole area cleared and I need mercenaries to do that.
Anyway, I'm continuing the storyline now, and when I'm done, I WILL start a new game just to get back to the Uberto assassination. It's just that I can't take it anymore right now.

Protip: copy over your savefile from before the Uberto assassination so you can go back to it at will without having to play through the entirety of the beginning of the game.

http://thehiddenblade.com/replay-ac1-and-ac2-story-missions-xbox-360

While I was walking around Venezia getting the feathers, I was testing different heights that are lethal to the rooftop archers.

I found a two store building, the tiniest drop death I could manage, less than this, the archer don't die:

I didn't throw him from there, I just place him above the street with the grab, so, no possible extra damage done.

Maybe this is the minimum height to kill someone?

It depends on the health of the target in question. Someone that was designed to fight is going to be tougher to kill.

#2 Vieri de'Pazzi

You might think Vieri is easy pickings for this challenge, since he's on a wall, but it's complicated. It seems he is immune to falling damage. I tried several places on the wall, lured him to a 3-story building, got him in an 'owling' position and punched him off (all of which would kill his bodyguards, btw), but nothing works.
Any ideas on what might work?

Maybe your best chance is to sliver his health to one Square and try to drop him.

San Gimignano is full of good drop spots.

Yeah

Probably only the targets that don't flee and fight to the death are hard nuts to crack through fall damage. But good thing they are very rare, most targets in AC2 are not quite fighters.

Targets who fight are Vieri de' Pazzi, Francesco Salvati, Dante Moro, Ludovico Orsi and Rodrigo Borgia. Everybody alse runs.

I hope I am not forgeting someone.

Uberto Alberti now sleeps with the fishes....

.....so I though, I used Aurel method to push him to the water, but the mission stuck after that, so I needed to reload and kill him normally, so, non-story assassination, bleh.

@gerund:

You can pre-assassinate all the guards in the area before Lorenzo and Uberto talk. The requiriment to remain undetected ONLY works after that talk, so is 100x easier to pre-assassinate them before the second part of this mission.