Ok, so I've been DMing for awhile and I keep getting tired of seeing great ideas and campaigns..... only for 4E. I am a 3.5 DM by nature and im very familiar with it.
-BUT-
I want to know some of the big differences between 3.5 and 4E, good things bad things, things to really consider, and major changes.
The differences are pretty huge.
1) The classes are more balanced with each other (I'm only considering PH1 and Essentials 1 classes). What is Essentials? Read on.
PCs get more hit points than before. The good news is monster damage is also higher, and combat is still deadly and (IME) exciting. The "bad" news is it's nearly impossible to kill a PC in a single round. So, a kobold can still kill a 1st-level fighter or wizard as easily as it could in 3e over time, but even an orc isn't likely to insta-drop a wizard with a crit. This gives PCs a safety net and makes lower-level more survivable (as if you get critted, you might choose to run rather than just ... die). Some people don't like that.
PCs have more healing options. Every PC gets a number of healing surges (a daily resource based on class and Con score) equal to 1/4 of their hit point value. Almost all healing takes up a surge, so you can't ignore damage all day. Every PC can use Second Wind. As a standard action, they can spend a healing surge and gain a minor defensive boost until the start of their next turn. It's generally the last healing option.
In addition, each leader class gets an ability like Healing Word, Majestic Word or what have you 2 or even 3 times per encounter that allows a PC to spend another healing surge, and usually gives bonus healing on top of that. These abilities are minor actions, so leaders can heal and do stuff they want to do in combat. I find clerics can, at low levels, effectively double the value of a healing surge.
Healing items, like healing potions, take a surge but give back (usually) less.
Before Essentials, each class followed an AEDU scheme. At-Will, Encounter, Daily and Utility powers. Each character gets basic attacks; these are standard weapon attacks (both melee and ranged). Each character gets at least 2 at-will powers from a list that give them various options over basic attacks (for instance, the fighter can take Reaping Strike, which lets them do a little damage even on a miss). Some characters, like the wizard, instead can use things like Cloud of Daggers or Magic Missile as an at-will, and these are nothing like basic attacks. Some people aren't fans of this (it means a wizard can cast a minor spell every round and never need use a crossbow).
The real cool stuff starts with encounter powers. Each encounter power can, of course, be used only once per encounter. Usually encounter powers deal more damage or inflict a nasty status effect, often something that enhances a character's role. Burning Hands is an example of an encounter power. Some people don't like how martial characters like fighters get encounter powers.
Daily powers are even more powerful. Many named spells from 3.x are daily spells now. For instance, Fireball, which does half damage on a miss. Many daily powers inflict a nasty effect on the victim until they save. (Legion's Hold, for instance, dazes and immobilizes the victims until they save.)
Utility powers tend to be defensive or skill-boosting powers. Classic spells like Stoneskin and Dimension Door fall under this category. Utility powers can be at-will, encounter or daily, but at-will utility powers are pretty rare.
Each class fills one of four roles: defender, striker, controller and leader. Each name pretty much does what it says on the tin.
An example of the defender are fighters and paladins. Defenders can usually
mark opponents, which draws their attention, inflicting a -2 penalty on the opponent's attack roll
except for attacks against the fighter. As defenders get high AC scores, you'd rather take the hits than a squishier wizard might.
The PH1 fighter has an ability called Combat Challenge. Every time it attacks something, even if it misses, it marks them until the end of its turn. In addition, if a marked creature tries to shift (the new 5 foot step) near the fighter or attack another creature, the fighter gets to immediately attack that creature. So naturally the creature "should" focus on the fighter. In addition, the fighter gets bonuses to opportunity attacks and can force a creature it hits with an opportunity attack to stop moving.
Contrast with the paladin. The PH1 version of the paladin has an ability called Divine Challenge. This is a minor action (swift action, in essence) that targets any enemy within 5 squares and affects it for the rest of the encounter. That creature is marked by the paladin. If that creature attacks anyone other than the paladin, it takes radiant damage based on the paladin's level and Charisma score.
Different, but both are "sticky".
Defender encounter abilities tend to enhance stickiness. For instance, the paladin's Piercing Smite ability marks all opponents next to whatever the paladin hit for at least 1 turn.
Strikers do damage. Rogues are the classic striker. So are rangers now. Rogues do sneak attack (naturally) anytime they gain combat advantage (that's the equivalent of losing your Dex bonus to AC), and many of their abilities let them gain combat advantage on a victim, so they can keep with the stabbing. Contrast with rangers, which can use Hunter's Quarry on a single opponent, doing bonus damage whenever they hit them. Strikers tend to have low defenses because players give them very high Dex scores, letting other scores lag. Note that wizards are
not strikers.
Controllers are supposed to inflict negative status effects. Wizards are the only controller in the PH. They have two builds: wand and orb. (Also staff, but no one plays those. ^^) Wand wizards are wannabe artillery. They don't deal high single-target damage but can use AoE attacks
at-will. (Truthfully any wizard can do this.) As an encounter or daily ability (I forget which), a wand wizard can use their Dex bonus in addition to their Int bonus when making a magic attack roll. Orb wizards (orbizards) tend to focus on save-or-suffer effects, and with their orb, can once per encounter or day either inflict penalties on a saving throw for one round or "repeat" an effect (so, if an effect dazes an opponent to the end of the wizard's next turn, they can extend that effect until the end of the wizard's next next turn instead.)
Some of the more flexible non-combat powers have instead become rituals. Those take a long time to cast (usually 1 or 10 minutes) and gold, but often have powerful effects.
Leaders are probably my favorite class type, especially the warlord. The two leader classes in the PH1 are cleric and warlord. As mentioned above, leaders have a minor action healing power.
The cleric has two builds in the PH1: "laser cleric" and "strength cleric". Laser clerics are my favorite. I've played a few clerics before and simply had no idea what spells to pick (compare to a wizard, where it was pretty obvious what to take). The laser cleric tends to take Lance of Faith and Sacred Flame as at-will powers. The former does radiant damage and gives an ally +2 to hit that target, while the latter gives an ally temporary hit points or lets them make an immediate save (the latter is sweeter than you probably think). Strength clerics often take Righteous Brand, which is a divine weapon attack. If it hits, allies get a bonus to hit that victim equal to your Strength bonus. Needless to say, cleric-flavored NPCs are hated by PCs, especially when they're giving attack bonuses to controllers!
Clerics get Turn Undead as an encounter ability. Unlike the 2e or 3.x versions, this is easy to understand. It does radiant damage to undead in a blast (half damage on a miss), and if it hits, it pushes the undead away and immobilizes them for a turn. Please note that most undead have vulnerability to radiant damage. A cleric can take a feat that lets it switch out turn undead (if it wants to, you don't lose turn undead) for an ability more closely associated with their deity. I found most of these abilities to be pretty weak, actually, and hopefully some non-core books have cooler options in them.
The warlord makes me drool, it's that cool for me. They come in two flavors as well, the Intelligence-based warlord and the Charisma-based warlord. Don't let the names fool you, Strength is your most important stat, a little sadly. One of your at-will abilities you can take allows an opponent to make a basic attack as a free action, which can be worth it because it also gives them bonuses. Use it on your most damage-dealing defender. Another attack lets you hit an opponent's Fort defense, doing minor damage but also giving an ally an attack against them. In fact, warlords are great at giving out attacks like that. An encounter ability, Hammer and Anvil, gives you a damage-dealing attack and also gives an ally one (with your Charisma bonus to their damage). The daily powers are almost scary; there's some that give all of your allies attack bonuses against the target for the rest of the encounter. Naturally you use that one first. An then there's utility powers like Knight's Move, which gives an ally a free move as a free action.
They also get Inspiring Word, a martial healing power. It doesn't seem very flavorful, but it means you can have a party without a cleric.
Monsters are also done up differently, designed to focus on simplicity. Most of the numbers are based on level. Most monsters have an attack bonus of level +5 vs AC or +3 vs non-AC-defenses. Their hit points are based mainly on level; rarely do you have a monster with a massive number of hit points but no special abilities (there are no 32 or 64 HD colossal zombies with a CR of only 11, doing massive damage but having poor AC and saving throws).
Monsters come in several roles: soldier (defender), artillery (striker), skirmisher (striker), lurker (something like a striker), brute (heavy) and controller. Note that leader is not a type by itself, instead leader is a "subtype" that's added to an existing role.
Skirmishers either get to move a lot, get special bonuses when they move, or both.
Lurkers focus on Stealth. Be sure to read the rules for Hidden Club before you use that skill; it's been errata'd too. A lot of lurkers can turn invisible.
Brutes do extra damage, have more hit points, and low AC scores.
Leader monsters rarely heal, instead giving bonuses to attack, damage, movement, etc.
Some monsters are elites or even solos. A solo is something like a dragon, designed to take on a whole party. The rules enable it to match a PC party's action economy, and give it special bonuses so it can't usually be taken down by a single control spell.
What is Essentials? This is somewhat controversial. WotC got some things in 4e wrong and essentially (heh) built a new set of core rules. So far the various PH1 classes have gotten new versions. They're compatible in the sense that you could have a PH1 fighter and an Essentials fighter in the same group, and there's no clashes. But you probably shouldn't let a PH1 fighter take Essentials feats or an Essentials fighter take PH1 feats, as they're not playtested with each other (probably, that is). The exception are some of the Expertise feats, but that's a topic for another day.
Most Essentials classes don't have daily abilities (certainly not the non-spellcasters). They have much less choice in abilities you can pick, making them seem like they're for "beginners" (whether this be true or not). The upside is it's even harder to make a weak PC using Essentials.
They also tend to be a little more true to their role (Essentials thieves, the equivalent to rogues, no longer have "control" abilities) and their abilities tend to be simpler to use, to the point that I often use Essentials rules when creating monsters. The Essentials wizard (the "mage") probably matches wizard flavor better, but seem a little more restrictive too. They have cool Enchantment and Illusion effects.
An element of inflexibility: they tend to focus on only one build (the Mage is the only exception to this). For instance, the Essential cleric, a warpriest, is only a Strength cleric. Not one of their abilities except Healing Word has range. There's no Lance of Laser Faith option
The hexblade is a very specific take on a warlock.
Now, i perused a 4E book once and after noticing that apparently that some alignments were missing and the whole planar system was rebuilt using some kind of "Primordial Chaos" crap i closed the book and said no way.
Poorly-explained alignments were removed. People didn't know what chaotic good or chaotic neutral meant, or what lawful evil meant. Some people thought WotC went overboard with dumping alignments. In any event, you can easily add those alignments back, and of course you can write descriptions of those alignments that actually make sense. Please note that alignments have effectively no metagame effect. There are no detect alignment spells, no alignment blast, etc. Artifacts that are based on alignment instead become "nicer" or "nastier" depending on specific actions -- the Hand and Eye of Vecna, for instance, become happier if you torture information out of someone (an evil act, and Vecna is the god of secrets) whereas it becomes upset if you kill undead. Paladins no longer arbitrarily fall (hallelujah, I might actually play one for once!).
Planar system is based on the setting, and the one you're seeing is based on the Nentir Vale Points of Light setting. I'm running Dark Sun and use its planar system. There's no problem at all. You're worried over nothing.
