- Estimated achievement difficulty: 4/10
- Offline: 44 
- Online: 0
- Approximate amount of time to 1000: 25-35 hours
- Minimum number of playthroughs: 1
- Number of missable achievements: 4
- Do cheat codes disable achievements: No Cheats
- Does difficulty affect achievements: No Difficulty
- Glitchy achievements: "Disciple of the Creed" [see achievement guide for more info]
- Unobtainable achievements: None
- Extra equipment needed: None
Assassin’s Creed does not have very difficult achievements, but there are a lot of collectible related achievements that can be quite time consuming. There are also a few missable achievements that this roadmap will prepare you for. As long as you are aware of all the achievements before going into the game, you should be able to 100% this game with a single playthrough. There are three main cities that you will visit three times each. In your third visit to each city, you will rack up the achievements quickly. You should be aware of https://www.assassinscreed-maps.com/, as using this site will make your job infinitely easier.
Step 1 – Missable achievements – 4 
There are four missable achievements that you need to be aware of before you begin the game. This is an open-ended sandbox game, so all the others can be completed at any time, even after beating the game, but these four take constant vigilance through your entire playthrough.
- "Hungerer of Knowledge": Your first memory glitch comes in your first memory, and every ensuing memory. I got lucky with this one on my first playthrough and got it during my final assassination. Just watch very carefully at every cutscene.
- "Conversationalist": This is the easiest to miss. I missed this on my first playthrough, and still have no idea where I missed. Just make sure that you talk to Lucy over and over again until she tells you to go lie down, every time you leave the animus.
- "Disciple of the Creed": This one should come naturally for most completionists. Just make sure that you complete all investigations, highpoints, and save citizen missions in the district BEFORE you carry out your assassination.
- "Blade in the Crowd": This only has to be done on one target, and most people get it on their first. If you miss this on your first target don’t worry, there are at least three other opportunities.
Step 2 – Masyaf – 4 
The game starts with a very linear introduction where you learn the controls and the basic premise of the game. There are three storyline achievements right off the bat, then you will be able to explore the city of Masyaf. Get the flags here using https://www.assassinscreed-maps.com/ for your 4th achievement.
Step 3 – Linear progression – 20 
Note: Absolute Symbiosis is not technically a linear achievement, but completing each district in a linear fashion will net you that achievement as well.
Step 4 – The Kingdom - 3 
If you are using https://www.assassinscreed-maps.com/ the kingdom is a breeze. Just go to each city, ticking off the kingdom flags that you get along the way. At some point, come through and get all the remaining flags, templars, and high points. If you aren’t using this site, I would recommend not getting any flags at all in the kingdom until you’re ready to do a flag hunting marathon. In addition to the Kingdom Flags achievement, this should complete your kill all templars achievement, and reach all high points.
Step 5 – Performance achievements – 13 
These are achievements like perform 50 combo kills, or assassinate 100 guards. Most of these will come naturally if you just don’t run and hide much. What I did to ensure that I got these quickly was to try to only kill guards using one method at a time, eg. I only assassinated them, then when I got that achievement, I only used combo kills, etc… The only one that might give you trouble is pickpocket 200(!) throwing knives, since you can only grab 5 at a time. Also, there’s no need to boost Eagle’s dance. If you just leap off every highpoint, you’ll get it eventually.
Note: See "Eagle’s Will" for a reliable glitch.
That should be 1000/1000. If you’re missing a flag, just go to https://www.assassinscreed-maps.com/ , clear all the flags in the area that you’re missing and and go through each flag location. Same with templars. Everything else should be apparent.