Okay, here's a quick primer that I did based on GamerMan's doc. Comments?
I'll probably go through the conversion manual and see if there is anything else worth adding, I just thought I'd give it a first blush.
A 3e primer for 2e Players
What follows is a quick summary of the D&D 3rd edition game for those only familiar with D&D 2nd edition. This document does not go into the same depth in converting 2nd edition characters as the Conversion manual does, and is more focused on the playing of the game.
The first rule of going from 2nd edition to 3rd edition
Leave all assumptions at the door.
The change from 2e to 3e is much more extensive than the change from 1e to 2e. The whole game was reworked from the ground up. The basic concepts (the basic races, the use of classes, levels, and hit point, "20 - good, 1 - bad", etc.) are still the same, but a great many things such as spell descriptions, the way ability scores work, class and race abilities, are all totally reworked.
Some of the changes may seem pretty baffling and hard to work through. But do not fall into the trap of thinking it is more complicated. It's not. It is new. After you have played it for a while, I think you will realize how much slicker the 3e system is. About the only thing I regard as genuinely more complicated than 2e is the attacks of opportunity rules. However, if you played combat and tactics, you already know the basics of that.
I ran a very extensive and detailed 2e campaign. When 3e came out, I had reservations about converting the game to 3e. For a short time, I ran both a 2e game and a 3e game. After a month, I was convinced that 3e was better and converted my 2e game to 3e. So give it a try!
I had a thick binder of house rules and tweaks I used to shore up the 2e system. Over half of the rules went away when 3e came along because it wasn't needed anymore. If that isn't a testament to the more straightforward nature of 3e, I don't know what is.
Basic character concepts:
Races:
The 3e PHB contains rules for making Human, Dwarf, Elf, Half-Elf, Half-Orc, Gnome and Halfling characters. Humans are now a worthwhile race and compare favorably with the other races. They gain an extra feat and extra skill points compared to
In the 3e game, it is sometimes possible to play a character of a non-human race, such as a centaur or ogre. Many creatures in the monster manual can have classes.
Any race character can be any class, as approved by the DM.
Classes:
The PHB has 11 classes in it. 8 of these you should be familiar with: Bard, Cleric, Druid, Fighter, Paladin, Ranger, Rogue, and Wizard. (What was once a thief is now more generally a rogue.)
The Barbarian and Monk are back from 1st edition. The Barbarian is a combative character, similar to a fighter. However, where the fighters receive extra combat oriented feats (see below), the barbarian receives a d12 for hit points, can rage, develops keen senses that help them avoid surprises, and have a selection of wilderness skills.
The monk is lawful in nature, and is always a member of a monastic order. Monks do not cast any sort of spells, but receive a number of extraordinary abilities based on their training. They do real damage with their hands, attack rapidly when unarmed or using martial arts weapons, receive an AC bonus when not wearing armor, and receive a variety of other martial-arts related abilities.
The Sorcerer is an entirely new class. A sorcerer uses the same spell list as a wizard does, but is slightly different. They are more natural or instinctive spellcasters; they use charisma as their spellcasting attribute (wizards use intelligence.) A sorcerer does not have to prepare spells ahead of time, and can cast more spells per day than wizards, but are extremely limited in the number of spells that they know.
There are other "prestige classes" that a character can take at high levels. The classes are detailed in other books, like the DMGs. Prestige classes usually represent specific guilds or orders with extraordinary abilities, and can make a more focused character concept. The prestige classes in the DMG include Assassins, Arcane Archers, Dwarven Defenders, and Loremasters.
Experience and Levels:
All characters use the same experience point table. It is no longer dependant upon class. If you have more than one class, you split the levels between the classes instead of splitting experience between classes. All characters receive extra ability points and feats as they go up levels.
There are no level limits by race in 3e.
Hit Points:
Classes use the same hit dice as they used in 2e. However, you do not stop rolling HD at 9th or 10th level. You keep rolling for HP up to 20th level. You add bonuses from constitution to each HD, as in 2nd edition. However, there are no limits on this according to class like there were in 2e. A wizard with an 18 Con gets +4 hp / level just like a fighter would.
Ability scores:
The same six scores are used as were used in 2e: Str, Dex, Con, Int, Wis, Cha. Characters receive an extra point that they can add to one of their ability scores ever 4 character levels.
There are no longer unique tables for each ability score. There is one table that governs all of the abilities; the only difference is how it is used. For example, a 16 strength gives you a +3 to attack and damage in melee, but a 16 dexterity gives you a +3 bonus to hit with ranged attacks and a +3 bonus to AC. There is no longer exceptional or "percentile" strength.
It is no longer necessary to have a 14 or greater score to get a modifier from an ability score. Every 2 points of an ability score increased a modifier by 1. For example, a 10-11 gives you no modifier, a 12 or 13 gives you a +1, a 14 or 15 gives you a +2, and so on.
Ability scores are no longer capped at 25, nor are there racial modifiers. If you have enough modifiers, you can raise strength to 25 and beyond. However, that is not as significant as it used to be. A 25 strength will put you on par with a hill giant, not a titan. However, the normal range for beginning human characters is still 3-18.
There are no longer strict requirements that characters of certain classes must have certain ability scores. Ability scores are a bigger part of class abilities, however, and spellcasters cannot cast spells if the ability score that they cast spells with is too low.
Charisma is more important than it was in 2e. It measures a character's force of personality, persuasiveness, personal magnetism, ability to lead, and physical attractiveness. It represents actual personal strength, not merely how one is perceived by others in a social setting. It is now used for things such as bard and sorcerer spellcasting, cleric's turning of undead, and paladin's saving throw bonuses.
Multi-class characters:
There are no racial restrictions on multi-classing, anyone can multi-class. Characters with multiple classes split their levels between their classes. However, all bonuses from each class are additive.
For example, a 4th level fighter / 5th level wizard would be a 9th level character, and the rest of his party would be likely be 9th level characters. The character roll 4d10+5d4 for HP, and would have the attack bonuses and saving throws of a 4th level fighter added to a 5th level wizard.
There are some restrictions. If the levels in your classes are more than one level different, you suffer an experience penalty unless 1 or more of your classes are a "favored class" for your race. For example, fighter is a favored class for dwarves, so in the above example, a dwarf never has to worry about the experience penalty. However, a halfling Fighter/Wizard WOULD have to worry about experience penalties if the levels were too far apart.
Feats:
Are special abilities, some of them combat-related. They aren't tied to any one class, but certain classes will be better than others at particular feats. Feats are "pick-and-choose" abilities that help make characters unique.
Characters gain one feat every 3 levels. Humans gain a free feat at 1st level, and certain classes gain bonus feats. For example, fighters gain extra combat feats as a class ability.
Skills:
Skills are the equivalent of 2e non-weapon proficiencies. They are purchased with skill points. Characters receive skill points according to class. At each character level, characters gain 2, 4 or 8 skill points (depends on character class -- 2 for cleric, 8 for rogue, for example), plus the character's INT bonus, plus one more if the character is human. At the first character level the skill point allotment is multiplied by four.
Your class determines which skills you can buy. You can buy skills out of your class list, but the cost is doubled.
Thief skills fall under the skill system as well. Rogues receive a larger allotment of skill points as part of their class abilities, and have access to the types of skills that were treated as thief skills in 2e (pick pockets, hide, move silently, etc.)
Special notes on Clerics:
"Spheres" are gone. All clerics have access to a general cleric spell list, plus they may pick 2 domains, which are in some ways similar to spheres. Each sphere includes a list of extra spells that the cleric can pick from and a special ability. A character's deity determines which domains are available.
Non-evil clerics may spontaneously swap prepared spells for healing spells of the same level. Thus there is no reason that a good cleric ever needs to memorize healing spells: you simply use your unused spells for healing.
For example, lets say a cleric of Meilikki has the 1st level spells bless, detect undead, and calm animals prepared (calm animals is a domain spell for the animal domain). During a combat, she uses here bless spell but not her other spells. She may use detect undead and calm animals as cure light wounds spells instead.
Combat and Wizards: Wizards can use a light crossbow, as it is part of the simple weapon proficiencies. A wizard may wear armor, but if they do so there is a chance of spell failure while wearing it. They may also suffer other penalties if they are not proficient in the use of armor (requiring a feat unless it is granted by a class ability).
Playing the game:
Rolls (Attack, Saves, Ability checks, and Skills):
Most rolls to determine success or failure of an action by a character use a d20. When such a check is called for, roll a d20 and add modifiers. To succeed, the total must equal or exceed a difficulty class (called "DC") of the task. This method is used for attack rolls, saving throws, and skill checks.
A specific example is the attack roll. As always, you roll D20 and add modifiers. However, there are a number of important differences:
There is no "THAC0". In 3e, a character's improvement in combat is determined by an attack bonus that comes from their class. In addition, Armor Class is the "DC" described above to the purposes of combat. In 3e, a higher armor class is better. An unarmored person with a dexterity of 10 would have an armor class of 10. All bonuses add to this. A armored person in +1 chain mail armor (which give a +5 armor modifier) with a +2 dexterity modifier would have an AC or 18.
As an example, if your character were a 5th level fighter with a 14 strength and a +1 sword, your character would have an attack bonus of +8. This includes +5 from being a 5th level fighter (remember, you get attack bonuses now instead of THAC0), +1 from the magic of the sword, and +2 from having a 14 strength.
For example, assume that your character is attacking the above character with an AC of 18. You would roll a d20 and add 8. If the total is 18 or more, you hit.
Once you have that mastered, you are ready to do almost any roll that the game requires. It all works the same way. If a wizard attacks you with a fireball, you get to make a saving throw for half damage, sort of like in 2e. The saving throw will have a DC (it would be around 15 for an average wizard casting a fireball). To make the save, you roll a d20, add your modifiers, and must get equal or above the DC.
Bonuses
One of the major problems in 2e was that it was rarely clear what bonuses would work together and which ones wouldn't. The language of spells and other effects often had to spell out what did and didn't combine.
It 3e, most bonuses to rolls and/or ability scores have a "type" associated with them. If you have two bonuses of the same "type" they do not stack unless otherwise stated. If they have different types or no type, they stack.
For example, if you are wearing chain mail armor, it provides a +5 armor bonus to AC. If you cast a mage armor spell, it provides a +4 armor bonus to AC. So you cannot use both; you would only benefit from the best (in this case, the chainmail armor). However, if you have a ring of protection +2, it provides a +2 deflection bonus to AC. If you wore chain mail armor and this ring, you would have a total +7 bonus to AC (for a total of 17). Also, if you have a 12 dexterity, you have a +1 dexterity bonus to AC, so that would stack too, for a total of 18 AC.
Combat basics:
Round are no longer 60 seconds (which you will already be used to if you played using Combat & Tactics in 2e) Combat is now real time, with 6 second rounds and players deciding at the time of their turn what they are going to do, so less bookkeeping. There are a number of combat options such as charge, sneak attack, move and attack, delay and full attack. Some feats are combat-based and can be amongst the possible actions that a player performs.
As mentioned earlier, instead of gaining a gradually decreasing THAC0, characters gain a gradually increasing Attack bonus, dependent upon class. All classes gain the ability to hit multiple times in a combat round, naturally fighters (and other combat-oriented classes like barbarians, rangers, and paladins) gain more and gain them earlier.
Initiative is a single d20 roll at the beginning of combat. The only modifiers that apply are the characters dexterity modifiers and possibly some other modifiers from feats and other abilities. Speed factor is no longer part of the game.
Critical Hits: In general a natural 20 is a potential critical hit. If you roll a "20" before modifiers (a "natural 20"), roll the attack again. If the second attack roll is a successful hit you have rolled a critical.
If you get a critical hit, you roll the damage for the weapon again and add modifiers, and add it to your damage. Some weapons allow you to roll 3 or even 4 times for damage on a critical hit.
Weapons
Weapons are classed as simple, martial or exotic. Almost all characters can use simple weapons. The fighter-type classes are able to use martial weapons; other classes must use a feat to learn to use a martial weapon if it is not granted as a class ability. All characters must spend a feat if they wish to use exotic weapons unless it is part of a class ability. Exotic weapons usually have qualities that make them worth the extra feat.
Weapons no longer have speed factors. The primary contrast between weapons is how often they score criticals hits and how much damage they do on a critical hit. Some weapons will allow you to roll for a critical if you roll less than a 20 (for example, long swords will allow you to check for a critical if you roll a natural 19 or 20.)
Armor:
As described above, a higher AC is better in 3e. There are limits to dexterity bonuses for wearing armor, dependant upon the type. An unarmored fighter has no limits to their dexterity modifiers, where a fighter in full plate cannot use more than a +1 dexterity modifier.
Saving throws:
There are three categories of saving throws: Reflex (dodge, area effect spells), Will (mind-influence, charms), and Fortitude (poison, etc.). As with attack rolls, you receive a bonus from your class and level. In addition, your dexterity modifier applies to reflex saving throws, your constitution modifier applies to fortitude saving throws, and your wisdom modifier applies to your will saving throws.
