As it says you must defeat 100 opponents without dying.
Spend the majority of your time blocking.
Always try and counter kill them as it is a lot easier.
Run around the city killing every guard you see.
If you are having trouble, this glitch works for some reason:
At the start of the game in Masyaf, run along the far left side of the village until you see a spiked outcrop pointing up toward the mountain with a tree just in front. If you run into the corner at the point while moving left and right, you'll be able to wriggle up the cliff face. When you reach the top, jump off the edge of the map and you'll unlock the achievement!
Credit goes to Mullock94 for the method and Moonska for the video.
glitch works...although this is an easy achievement, if you want to do the glitch (i did on another account because it was funny) just go up the mountain in the vid and jump backwards...i find it entertaining
I used the glitch for this one, but if you want to do this legit, then run around killing guards in the Kingdom. If you're in a fight with low health, start running in circles. The guards will just keep chasing after you while your health slowly regenerates. If you find the sweet spots on your controller, you just have to hold LT(sprinting) and the joysticks in one position the entire time. That's what I did towards the end. Just make sure you have enough space to run in circles :)
I just played this game for the first time on my gamertag. Right after the Animus tutorial, when the game begins (in the sanctuary or kinda like that), after killing the guard and the little cutscene I tried to jump to wall to hang from it but the guy decides to jump to the outside of game area, so I fell down and got this achievement. I mean how come this isn't patched for after so much time?
I got this achievement by jumping off the cliff as well, but I also got the Eagle's Challenge achievement at the same time! Really weird, I think it may have been because I just finished fighting before I did the glitch. Try it and see if the same thing happens to you...
I can't get this video to work on the iPad or the phone or the PC, but YouTube was a great help. There's several easy-to-follow videos on there on how to do the glitch, which still works almost 5 years after the game's release, meaning no patch. But if you know how to block and counter, this shouldn't be too hard to get legit anyway, only time-consuming. But hey, that's what Assassin's Creed is all about!!!
Too easy to do in Masyaf in the first part when you have all of your skills. Just head to the first intersection that splits and wait there....they will come at you one at a time. Yeah it was boring but it was easy. And that nets you Eagle's Flight because of the time and other achievements if you kill them different ways.