There are two basic ways to fight, solo (by yourself) or in groups (with other people). Both solo and group fighting has advantages and disadvantages.
Solo Fighting
In solo fighting it is you against the hordes of Withered Aegis creatures and monsters. If you cannot heal yourself (cleric or Healer adventure schools), then fighting will take longer. Lag is not an issue and all experience points and loot go to you in solo fighting. Since you are not fighting in a group however, there will be no group bonus experience points.
Group Fighting
While fighting in a group, you will gain group bonus experience, the coin loot will be evenly distributed, and the base experience obtained for a kill depends upon how many hits you get in. If you have a Cleric or Healer in the group, the group can fight higher level mobs and kill faster meaning more experience in less time. However, lag can be a serious issue and other than coin loot is not distributed. And of course there are courteous players and disdainful players so chose your group companions carefully.
To be courteous in group fighting, share turns looting the corpses. When you see a group member "tanking" (that means losing hit points and about to die) heal them. If you are going to be gone for long periods of time (5 minutes or more), then remove yourself from the group and let them know what is going on and if you'll be back or not. Protect the melee fighters first, then worry about getting hits in on the mobs.
To start a group, you can open your Group window (blue button - Group) and invite people to join. There are two ways to invite people two join. You can right click on the player and left click on invite to group or you can send the text command in a chat window: /groupinvite playerfirstname. The text command sends a group invite to the player no matter where they are in the world of Istaria. In the vein of being courteous, ask a player before blindly sending them an invite.
Abilities
Every adventure school has it's own set of abilities. Abilities are granted based on level and a message will be displayed upon level up on what new ability if any has been granted. Abilities are usually granted on even numbered levels. These abilities aid you in fighting. Some abilities are passive, meaning you don't have to activate them manually, they are activated automatically. For the activated abilities, you can open you character window, go to the abilities tab, click the adventure button, and drag the ability icon onto a hotkey bar. This will give you an easy way to activate an ability in the heat of battle.
Combat Stance
There are four combat stances that play a large role in fighting and can mean the difference between wining and losing a fight. These stances are neutral, red, blue, and green. These stances are abilities and can be put on hotkey bars. If the monster is neutral stance, pick red for yourself. If the monster is red stance, pick blue for yourself. If the monster is blue stance, pick green for yourself. If the monster is green stance, pick green (least damage to you) or red (most damage to monster) for yourself. Fighting always in neutral stance can also be done and when in doubt what stance the monster is in, choose neutral.
Loot
There are certain techniques that are only available through monster drop, Power Shot and Power Strike are prime examples. After a Golem has been killed, it can be mined. Some monsters will drop occasional, random items such as lore tokens, forms and techniques. Monsters also drop unique items useful for applying a technique to an item. For example a Granite Golem may drop a Granite Golem Fragment, a Zombie may drop a Zombie Finger. These items are used for applying various techniques to items during crafting.
Experience
Once above level 18 or so, killing a monster equal to or 2 levels above your current adventure school rating will gain you 2% of a level. This means to level, you must kill 50 monsters equal to or greater than your current level. If fighting in a group, you may have to kill more than 50 but they will come faster. Monsters below your level will result in less experience and eventually no experience at all.
Multi-classing and Overall Rating
Your character can level in multiple schools, for example Cleric and Warrior. This is called multi-classing. When you do this, your character will have a current adventure level rating and an overall rating which will be higher. For example you could be a level 23 mage, level 23 warrior and a level 41 cleric but in your cleric form, your overall rating would be 44. The overall rating affects how much damage you do, how much damage you receive, and how much experience you gain. Multi-classed characters are more rounded and capable but often find it more difficult to level. You can level other schools to master a given ability, but beware, not all abilities can be mastered. The ability itself will tell you if it can be mastered.
Combat Tactics
Monsters above level 6 or so agro bad. This means they group up on you and will initiate an attack on you. So don't wade into the middle of them. Rather, pick one off, let it follow you away from the crowd and fight it. It is best to watch the pattern the monsters follow in their travels so you can pick a safe ambush point.
Don't be afraid to run. The better part of valor is knowing when to retreat. If you are losing more hit points than the monster and you are between 50% and 25% of your hit points, then run Forrest run! Live to fight another day.
Dying and Death Points
When you die, you can recall to the shrine you are bound to and will be resurrected but with a "death point". Clerics can resurrect you on the spot. Death points take 8 hours to automatically rescind unless you consume food from a confectioner or ambrosia from an ambrosia vendor. Ambrosia specific to your level is available at ambrosia dealers which are always close to the shrines in the non-player towns. Death points detract from your skills and reduce your fighting prowess. Luckily when you die, you don't lose everything in your inventory, you get to keep it. After accumulating a few death points, it's always best to go craft or log out for a while. Death point timers are stacked but time out even if you are not online. For example, 2 death points will take 16 hours to tick off, even if you got them immediately together and you can log out and come back 16 hours later and the death points will have timed out.
And lastly
Learn your character, no class has to group to progress. Grouping is easier but not necessary, any class can solo. Solo ALOT to learn how to fight your character and get an appreciation of the game and interaction.
