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 NPCs. For example, when being pursued by bounty hunters on ‘Normal’ difficulty, the chances that you encounter multiple bounty hunters at once are lowered. Conversely, on ‘Nightmare’ difficulty you may be ambushed by numerous bounty hunters with all kinds of mean tricks up their sleeves such as fire / poison arrows, vicious pet companions or special moves such as heavy charges and swift flurry attacks. The rate at which these encounters occur while you may be minding your own business fighting in an outpost also increases between Easy to Nightmare. Naturally, you can expect more of a challenge as you increase the difficulty.
Guided mode ensures that all main and side quest markers are displayed on the map. This includes any objectives which are pending completion before you can progress with the story. It will direct you to relevant quest positions and points of interest 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 an objective, you will need to follow hints related to the relevant objective. These hints are displayed in the top left corner of the screen when viewing the map interface.
The good news is that you can alternate between both Guided and Exploration mode at will throughout the game. If you decide to play in exploration mode most of the time but occasionally find yourself stumped by a particular quest objective, you can briefly switch back to Guided mode in the Gameplay options menu.
Once game mode settings are established, you must choose one of two possible characters to play as; Alexios and Kassandra. Note that your choice will not influence the progression of the story. Each character will take the place of the other in the story, depending on which you choose. The only thing implicated in your choice is aesthetic preference. However do note that of the three main options detailed here in the introduction, this is the only one which is permanent and cannot be changed later on. The game difficulty and game mode can be altered at any point during gameplay.