The prologue begins at the Battle of Thermopylae; the battle fought between an alliance of Greek city-states, led by King Leonidas of Sparta, and the Persian Empire of Xerxes I in c. 480 BCE. You are thrown into the midst of battle on the second day, playing as King Leonidas. The purpose of the prologue is to familiarise the player with the basics of combat. In the heat of battle you will learn how to execute basic attacks and one special attack in the form of a charge. You can then move toward the quest marker to initiate the next phase of the tutorial.
Here you will be fighting a Persian named Kurush in a kind of brief boss encounter. Unlike the previous opponents, he carries a shield. This provides the perfect opportunity to learn heavy attacks, which are required to break through the defences of an advanced opponent. In addition you will learn how to perform a dodge and an extended dodge to avoid their retaliative blows. Once you have defeated Kurush the basic combat tutorial ends. A brief cut scene follows, after which you are transported to the future where you will enter the Animus.
Before being transported to Ancient Greece you have three main options to consider. These options constitute the following:
Easy - Normal - Hard - Nightmare
These settings primarily tweak enemy health and damage during fights, but they also impact the behaviour and intelligence of NPC’s. Naturally, you can expect more of a challenge as you increase the difficulty.
Guided mode ensures that all main and side quest markers and objectives are displayed on the map. It will direct you to the relevant positions with the least amount of environment investigation necessary.
Exploration mode removes all main and side quest markers from the map. Instead of indicating a direct path to the objective, you will have to follow hints related to the relevant objective, which are displayed in the top left corner of the screen.
Choose between two possible characters; Alexios and Kassandra. Your choice will not influence the progression of the story. It comes down to a matter of aesthetic preference. Of the three main options listed here, this is the only one which is permanent and cannot be changed later on. The game difficulty and game mode can be changed at any point during gameplay.