Assassin's Creed references...
	How to see all 16 endings...
	Move faster...
	Rolling for the win...
	Secret Achievements...
	Various Achievements...

During the "Prologue - Barricade" mission, where you must destroy a gate by using a ballista, drop down the wall to a series of scaffolding then reach the ground. Fight several soldiers from the rebellion group and make your way to the guarded ballista. Kill the enemies and clear the square, then go further back from the ballista and look to your right, beside a house. You will find a dead man dressed in a white robe with a red belt laying face down on top of a broken hay wagon (a reference to Altair Ibnu La Ahad). Look up to see a wooden ledge with a bird, which is where an assassin would usually survey the surroundings (synchronize) and perform the leap of faith. Geralt will say "I guess they never learn".

You can also get a hidden ability named "Assassin" that gives a damage bonus on the attack that lands on enemy's back, This is a reference to the back stab assassination in Assassin's Creed.

Here is a summary of choices you have to make to achieve all 16 endings.

Aryan Dies
Iorveth Path - Stennis killed.
Iorveth Path - Stennis spared.
Iorveth, Triss Path - Stennis killed.
Iorveth, Triss Path - Stennis spared.
Roche Path->Henselt killed.
Roche Path - Henselt spared.
Roche, Triss Path - Henselt killed.
Roche, Triss Path - Henselt spared.

Aryan Lives
Iorveth Path - Stennis killed.
Iorveth Path - Stennis spared.
Iorveth, Triss Path - Stennis killed.
Iorveth, Triss Path - Stennis spared.
Roche Path->Henselt killed.
Roche Path - Henselt spared.
Roche, Triss Path - Henselt killed.
Roche, Triss Path - Henselt spared.

Get one of the first Warrior path skills. This is unlocked at level 6 or 7 by spending points into the Witcher path. The Warrior skill allows you to dodge further distances. Level 1 is 100% and level 2 is 200%. Take out Geralt's sword and begin rolling when in a wide open area or deserted portion of a city. You will be able to travel faster than normal. If timed precisely you can roll without pausing between rolls. Note: Having your sword out will draw the attention of the guards.

An easy way to make Geralt faster early on is to get one of the first warrior path skills (unlocked at level 6-7 by putting points into the Witcher path). The warrior skill allows you to dodge further distances (level 1 is %100 and level 2 is %200). When your in wide open areas or even in a deserted part of a city, pull out Geralt's sword and start rolling. This will get you wherever you want to go much faster, because if you time it right you can roll without pausing in between rolls.

Note: If you try this near guards they may start to pursue you, just put your sword away as soon as they try and they will leave you alone.

Achievement	How to unlock
Artful Dodger ( 30 points )	Cut off a tentacle using the kayran trap.
Avenger ( 30 points )	Finish the game by killing Letho.
Backbone ( 20 points )	Craft a suit of armor from elements of the kayran's carapace.
Being Witcher George ( 20 points )	Kill the dragon.
Black Ops ( 20 points )	Sneak through the lower camp without raising the alarm.
Dragonheart ( 20 points )	Spare or save Saskia.
Eagle Eye ( 10 points )	Hit Count Etcheverry using the ballista.
Fat Man ( 15 points )	Kill the draug.
Friend of Trolls ( 15 points )	Spare all trolls in the game.
Heartbreaker ( 10 points )	Seduce Ves.
Intimidator ( 15 points )	Intimidate someone.
Kayranslayer ( 10 points )	Kill the kayran.
Kingmaker ( 15 points )	Help Roche rescue Anais from the Kaedweni camp.
Librarian ( 30 points )	Find all additional information about the insane asylum's history.
Man of the Shadows ( 15 points )	Successfully sneak through Loredo's garden and find the component of the kayran trap.
Necromancer ( 50 points )	Relive all of Auckes's memories in Dethmold's vision.
Old Friends ( 30 points )	Finish the game by sparing Letho.
Reasons of State ( 15 points )	Stop Roche from killing Henselt.
Sensitive Guy ( 10 points )	Save Síle from dying in the unstable portal.
Spellbreaker ( 15 points )	Help Iorveth find the dagger needed to free Saskia from the spell that holds her.
Tourist ( 10 points )	Tour the camp with Zyvik.
Trollslayer ( 30 points )	Kill all the trolls in the game.
Witch Hunter ( 10 points )	Leave Síle to die in the unstable portal.

Complete the following achievements to unlock Xbox Live Gamerscore points.

Achievement	How to unlock
Alea Iacta Est ( 10 points )	Complete Chapter 2.
Apprentice ( 10 points )	Use alchemy to brew five potions or oils.
Craftsman ( 10 points )	Hire a craftsman to create an item.
Focus ( 30 points )	Perform three successful ripostes in a row.
Gambler ( 15 points )	Win an arm wrestling match, a dice poker game and a fist fight.
Gladiator ( 15 points )	Defeat all opponents in the Kaedweni arena.
Guru ( 50 points )	Achieve character level 35.
Journeyman ( 10 points )	Achieve character level 10.
Last Man Standing ( 15 points )	Survive your 30th fight in the Arena
Madman ( 100 points )	Finish the game while playing at the Dark difficulty level.
Master Alchemist ( 10 points )	Acquire the Mutant ability.
Master of Magic ( 10 points )	Acquire the Sense of Magic ability.
Miser ( 10 points )	Collect 10000 orens.
Mutant! ( 30 points )	Enhance abilities using mutagens at least five times.
Once Ain't Enough ( 15 points )	Complete Chapter 3.
Perfectionist ( 15 points )	Kill 10 foes in a row without losing any Vitality.
Pest Control ( 20 points )	Finish all quests involing the destruction of monster nests.
Poker! ( 30 points )	Roll five-of-a-kind at dice poker.
Ricochet ( 10 points )	Kill a foe by deflecting his own arrow at him.
Swordmaster ( 10 points )	Acquire the Combat Acumen ability.
The Butcher of Blaviken ( 30 points )	Kill 500 foes.
The Fugitive ( 5 points )	Complete the Prologue.
Threesome ( 15 points )	Kill three foes at once by performing a group finisher.
To Aedirn! ( 5 points )	Complete Chapter 1.
To Be Continued... ( 50 points )	Finish the game at any difficulty level.
Torn Asunder! ( 15 points )	Kill more than one opponent using a single exploding bomb.
Tried-and-True ( 10 points )	Survive your 5th fight in the Arena