This is a list of all gameplay bugs that have been discovered in Assassin's Creed.
A second Altaïr sometimes appeared while riding away from Masyaf on a horse, triggered by going between two pillars. On the right pillar was a surrounding glow, usually associated with targetable objects or people. Investigating this yielded a second Altaïr. When targeted, the second Altaïr mimicked the original exactly, in such a way that if one Altaïr punched the other, the double would punch back. Accompanying this, if the original Altaïr assassinated the clone, it would cause desynchronization.
During the return to Masyaf in the final memory block, walking into the mountain near a market stall during the first combat sequence made Altaïr unable to escape the mountain, though it was still possible to attack guards who came close to the rock face.
In Assassin's Creed, Assassin's Creed II and sometimes in Assassin's Creed: Revelations, climbing a wall, or a box on a wall, rarely allowed the Assassin to go through it and become stuck. The only exit was to drop, which made them fall for a few seconds before landing in invisible water. In Assassin's Creed, desynchronization followed, but in Assassin's Creed II and Revelations, Ezio could swim around.
Sometimes, in the Kingdom, at least one of the more heavily guarded View Points had two climbable wooden structures that could break during battle. On some occasions, a guard could become stuck inside one of the wooden structures, unable to move or attack, though Altaïr could attack them from below while on foot.
Sometimes if Altaïr threw an Archer from a rooftop, they would survive. Following this, if the Assassin then hid, the archer would go to the ground and became a normal guard, with an identical archer replacing the previous one's position.
Outside of Damascus, two guards stood on a cliff. If Altaïr pushed them off, one would miraculously survive and begin searching for the Assassin, as guards normally would. Any means of returning the social status to "Anonymous" would allow Altaïr to avoid the indestructible guard.
Sometimes in Damascus, scholars would appear on top of buildings. Though this bug was very rare, it would only appear if scholars had run off before they had come back later on.
Guards in MasyafEdit
When Altaïr ran into any guard standing outside of Masyaf's fortress and then hid in the haystack near to the gate, the guard would begin to walk like a regular city guard and could enter the castle with the civilians. If the guard was disturbed again, he would begin to chase Altaïr, even in the fortress where weapons were restricted. Once Altaïr tried leave the fortress during a chase, he would become desynchronized upon passing through the gate, and the Assassin would continue to run uncontrollably.