I just recently started playing Assassin's Creed: Brotherhood on the PC. When I started Sequence 2, there is a mission where I have to tackle a guy who stole my money. I keep chasing him, but I can't find a reliable way to tackle him.
The "Shift" key contextually changes from "Shove" to "Tackle" but I can never manage to consistently execute the tackle. In general, I leave it up to chance and somehow I get it to trigger. I also can't figure out how to shove people either. Usually I just end up falling into them and tripping.
I had this same problem in Assassin's Creed 2, but I managed to get through the whole game without really needing to perform either of these moves.
Best Answer
To Tackle someone you need to:
Be in high profile mode, by holding the right mouse button.
Be running, with your legs, by holding Space or the 4th mouse button (5-button config).
Tackle them with your free arm, by tapping Shift or the 5th mouse button (5-button config).
To Shove people you need to:
Be in high profile mode and running with your legs.
Be ready to shove with your free arm, by holding Shift or the 5th mouse button (5-button config).
Run in to them. As long as you're holding your free arm ready they will be shoved aside.
I also found it a little bit awkward to reliably tackle the correct target, but in general you should be close to and running towards the target when you tap the free arm button, and ideally not when near other people that might be targeted by mistake.