Pros

It is one of the few true PVP games made. In DAOC it is called RvR (Realm vs Realm). The core of the game is PVP and the remainder of the PVE content is built around this conflict and supports it. Most MMORPGs are PVE based and then just adds a PvP angle.

Realm V Realm is a contest between three sides. Most Games seem to be happy making 2 sides (one good one evil generally speaking). In daoc there are three. So its a unique feeling that you could be fighting one enemy and always in the back of your mind you are worried about the third realm ..will they help us? help them? or kill us both?

The esprit des corpes is something that is not often seen in most games. When you chose a side you must play that side. you cannot play all the realms on any one server. So in chosing you truely feel like a member of that group. Clustering has diminished this soemwhat but it generally still holds true. Now, understand that there are jerks in every game. So finding a good guild or alliance where the community is still fairly loyal will make your in game experience a LOT better.

Its casual player friendly. The level grind is very quick. The best weapons are player made and available. Equipment discrepencies do not have as much an impact as in other games. Thus someone in average gear can still take on and beat someone in ultra God mode gear. Solo play is available and you can solo up to high levels.

You can start fighting right out of the gate. The battlegrounds are small  instanced areas where you can fight at any level again similarly leveled opponnants. These can be great fun. Most people don't goto the battlegrounds below lvl 19, due to the /freelevel system. However, some do for kicks.

There is a HUGE number of player classes. Each with thier own abilities and function within a group of battle. Within each class there are specialization choices. This basically gives a wonderful feature of replayability. Many people have 4 , 5 or even 6 classes they enjoy.

Siege warfare. This game has a very robust and balanced siege system. Likely the best yet seen in any MMORPG. The attacks on castles and towers constantly occurs and is a great event. Scores of payers atacking and defending the walls/towers and rooms inside the castles (Keeps). Catapults, Batlle Rams, Boiling Oil, trebs, etc...are all here. This is one of the few games where the siege combat is very well developed. In the frontiers each realm has 7 keeps each one surrounded by 4 towers. Both Keeps and towers can be attacked individually or at the same time. As an attacker you are able to produce weapons to assist you in attacking and gaining control of your opponants towers or keeps. As a defender you can also construct siege weapons to attack opponants or destroy their siege machinery. A full scale keep siege is a thing of beauty. The walls become damaged and crumble leaving large gaps through which your force can charge through. Entire towers can be razed to the ground producing a cloud of dust and debris. One of the biggest draws to siege warfare is that this game gives you a reason to attack the castles. conqueing towers prevents easy access for defenders to quickly mount a defense and gives bonuses to your entire realm in XP or money that you recieve as you grind. It also opens up control of a PvP dungeon to your realm called Darkness Falls which is by far THE best place to level your character (or alts). Succesful control of many keeps will open up that realms relics which then you can steal. By doing so you make your realm stronger (In magic or melee ..depending on the one you take) and the victimized realm weaker.

Cons

It had a disasterous expansion called Trials of Atlantis (TOA). Similar to SWG (star wars galaxies)  it changed the game drastically and in many players views killed the game. Fortunatly (and unlike SWG) it made a classic server that eliminated this expansion from the game. These Classic servers are the most popular to play. However, let me add that not everyone hated ToA.  The subscription numbers actually went up with ToA and only declined when WoW came out.  ToA is an expansion.  An expansion that added raids, uber loot and new abilties but did not change the fundamentals of the game (as what happened in SWG).

It has a buff bot problem. Buff bots give a significant advantage over players who do not have them. These are quite prevalent on the main servers. Fortunatly on classic servers this is also rectified and buffs have a range after which they are lost. Because of this some players place a buff bot on autofollow behind thier main fighting character. In this case they can still be a deadly force, but at least you have the ability to attack the bot. Whenever I see this I make it a special point to kill the bot first, even if I die ....players get especially angry when you kill thier bot..and that is a source of my joy.

A siege can be a very long ordeal if defended well. Sometimes this adds to the frustration. Also when it comes to keeps and towers the melee classes really lose out. Since they generally stand around whacking a wall or door the whole time while archers, casters, and stealthers are fighting a ranged battle on the walls (this may have changed). In my opinion ranged DPS have a distinct advantage over melee DPS. Recently, Heavy tanks can now climb walls and you can now construct siege ladders. This was a very welcomed change ..however, many people found out that storming up the keep walls (without stealth) was jumping out of the frying pan and into a fire (where you had no line of sight to be rezzed)   Heavy tanks are used for rams and generally run the other siege equipment as well. It should also be noted that recently the developers added "free lvl 10 keeps", or in other words keeps no longer require bounty points to progress to lvl 10 (the toughest kind of keep to attack). This has angered the some players.

As with all PvP games class balance is a fine line. Mythic has taken the stance that it doesnt balance classes but balances sides. Because of this you may find there are just some classes you have very little chance against. The game assumes you will have a complimentory group at your side. obviously this is not the way things work in practice. However, unless your a stealther, players learn to stick together and safety comes in numbers. This also adds to the esprit des corpes mentioned above. To Mythic's credit, given the sheer number of classes in this game, they have done a pretty good job.

The economy is probably the most fragile aspect of a MMORPG. In the beginnning it is solid, because there is little currency in the system. however, as a game gets older more and more money are placed into the syetem and thus devaluing it. Since this game is now 7 years old, the currency is not as valuable and items bought at player run vendors and crafter services tend to be higher. However, if you sell items or services you can charge more money for them.

Its an old game. The future of it is unclear. How will it coexist against Mythics upcoming project WARHAMMER online is unknown. It may be the last hurrah for DAOC, as many of the current DAOC players will move to WAR upon release. There are rumors that DAOC will become Free to play (F2P) upon the release of WAR, but this is only player speculation and there has been no official announcement from Mythic to this.