Praise the sun. Our Dark Souls Walkthrough provides tips for surviving the adventure, a guide to the entire world, and hints for slaying bosses.
Equipping
Before entering battle, you'll need to be armed for the fight. It is possible to fumble around the menus while already in combat, but will probably prove too distracting to be practical. The main thing to factor in is the size of your Equip Load, which will greatly affect your fighting style.
Equip Load
Your Endurance score will grant additional numbers to your max Equip Load. Each piece of armor your wear and weapon in your hands adds weight that will slow down your movement. When your Equip Load is less than 25%, you may run at high speed and will roll quiet far. At 26-49% your movement is slowed slightly, but still enough to dodge around enemies. When you have over 50% of your load, running is slowed down considerably, and your roll is more of a quick thud onto the ground. Finally, with over 100% of your Load, you will be unable to run and your rolling is replaced with a short forward stomp.
To help balance out your load, you need to be mindful of your equipment. Stronger weapons and better armor typically will weigh you down, but some of these items might be very powerful or prevent staggering. The Poise stat on heavy armor can help withstand the most potent attacks, allowing you to strike and heal even when being hit.
Lighter characters can move much faster.
Your movement and defense style really varies from enemy to enemy. In some cases you need that extra mobility to safely dodge those attacks. On other foes, straight defense will keep you from being pushed or knocked down. You should be prepared to change your armor and weapon sets depending on what you're up against.
Defense and Resistance
Each piece of armor has six different types of defense and four resistances. An armor will favor one or more of these properties, but will have a weakness in some area. Because of this, you should be mindful of what armor you wear for different foes.
An armor's physical defense is further broken down into three types: Strike that protects against blunt force attacks, Slash for swords and clawed swipes, and Thrust which guards against spears and arrows. When you check a piece of armor, it will only display its base physical defense, but you can hit the "Toggle Display" button to gain additional information. Armor will also reduce damage from Magic, Fire, and Lightning. In general, Lightning defense is the hardest to come by, so any piece that protects against shocks is valuable.
Armor also has four types of resistances for abnormal status. The first value is Poise, which isn't a true status effect, but will help prevent being stunned and knocked down. Lighter clothes typically have no Poise, but heavy plates and stone mail offer high staggering protection.
Your equipment and natural ability scores will also protect against two types of damage over time: Bleed and Poison. Bleeding typically happens from getting hit by piercing daggers and other weapons. Poison is most likely part of an enemy's main attack, but can also be caused by stepping on poison ground or water. You aren't hit with either of these two status abnormalities immediately. Instead, a "build-up" meter will appear and when the gauge fills, you will be afflicted. Bought or farmed healing items--such as Moss Clumps from Darkroot Wood--can be used to cure Bleeding and Poison.
There is also the ever deadly Curse. You have no natural protection from this ailment, but can boost resistance from armor and by being in Human form. If your Curse build-up meter does fill up you will instantly die. Upon revival you will be at half health, and curses can stack until you're at an eigth of your life. If you do come under Curse, you will need to use Purging Stones sold by NPCs at the top of Undead Parish and Undead Burg sewers. You can also take a journey into New Londo Ruins for a cure that costs Humanity, but it can be very difficult at even high levels.
In Your Hands
You can equip up to four different items in your hand slots. All heroes in Dark Souls are right handed, so main attack weapons should be placed in the right, while off hand weapons and shields go in the left.
Main hand equipment usually have a normal attack and a slower, yet deadlier power attack. In some cases, as with the Halberd, this power attack delivers a sweep. Your shield and off-hand weapon can be used to block in coming blows, parry for a counter, or even quickly attack. While guarding with heavier shields will nullify all damage, blocking with a sword or dagger will still result in receiving some damage. Rapiers and other swift weapons typically parry instead of outright block, allowing you to deliver a powerful riposte.
You also need to place spell casting items: staves, flames, and talisman in one of your free hands. This means that you have to forgo equipping an extra weapon to make up for these slots. If you're mixing magic school together, you might find that you have no room for even a melee weapon.
Additionally, you will need the required Strength, Dexterity, Intelligence, or Faith to effectively wield a weapon. If you lack one of the key stats, your swings will be wobbly, weak, or you may simply scratch your head while attempting to cast. In some cases, weapons that are too wily for use in one hand can be used in two hands. You can quickly change to holding your right hand weapon in both hands, resulting in more control and power.
Not only does your hand equipment have requirements to use correctly, it also receives a different score from each of the four attack stats. You might pick up a rare holy sword that uses both C ranks of Strength and Faith to determine its power. Other items might have an A rank (or even S rank) in a single stat, making it only viable for builds that pumped up that stat.
Be Ready for Any Situation
As with armor, you will need to change equipment to fight various type of enemies. You might find that some beasts are immune to Flame or Physical damage, while other creatures fly and require some kind of ranged attack. Other times you might need the biggest weapon to crack a foe's heavy defense.
For example, an agile spellsword might want to consider having a spear and casting staff in their right hand, while a shield and rapier are in their left palms.
