OK, so, to begin: you are going to get +2 Dexterity, which is nice-ish, −2 Constitution, which sucks but at least you’ll get bonuses and d12 HD, and you will get a bunch of other stuff that barely matters at all. For reasons, you probably will not be using any traditional elven weapons (though the less traditional elven-specific weapons in Races of the Wild are solid options in a couple of cases). Thus, your elven race would be a moderately-large downside, a sort of mediocre ability score bonus, and not much else.
The solution to this is taking advantage of various elf-only options. That means you are going to need Races of the Wild, since that’s where most of them are, and Tome of Battle, because there’s two excellent things in there for you.
There are three primary prestige classes I have in mind: champion of Corellon Larethian, eternal blade, and wildrunner. They do not all work together, sadly, at least not completely, but we can still work with this.
Champion of Corellon Larethian—more knightly/paladin-y than you’re looking for, but two levels do allow you to add your Dexterity bonus to damage with certain weapons. That’s very valuable. Unfortunately, requires a stupid number of feats, too many to make workable, and the elegant strikes feature (read: the reason we care about the class at all) is incompatible with Shadow Blade (which does the same thing for a different set of weapons, and for fewer and better feats) unless you get a favorable ruling about elven lightblades and Shadow Blade.
Eternal Blade—this thing just oozes cool—it’s basically Link, Hero of Time. Furthermore, the capstone is extremely useful: once per fight, take two full-attacks in a row. You will be a crazy frenzy of blades.
Wildrunner—this is the big one, the crazy elven barbarian. It gains a “primal scream” class feature, which works very similar to rage, and stacks with that. Notably, it has a big +6 bonus to Dexterity.
Feats
Your first feat has to be Weapon Finesse. You have a bonus to Dexterity, this build relies on Dexterity, and you have to be able to hit things. What this means is, unless you have Flaws from Unearthed Arcana, you will not be able to get the Two-Weapon Fighting feat until later. Even with them, because of the feats you need to get that are not fighter-bonus-feats, with flaws I still recommend delaying Two-Weapon Fighting in order to ensure other feats on time.
If you do not have Two-Weapon Fighting, you should not attempt to use the two-weapon fighting combat option. Sorry, but you only get one feat, you are going to have to be Dex-focused, and without Weapon Finesse a Dex-focused melee fighter isn’t going to hit anything.
After Weapon Finesse and Two-Weapon Fighting, the next priority is Shadow Blade, from Tome of Battle. This allows you to add your Dexterity bonus to damage when using one of a selection of weapons—the short sword is the one for you. The issue is getting a Shadow Hand stance to use it with. This either means Martial Study and Martial Stance before you can get it, or taking a level in swordsage. The problem with the latter is it will slow down entry into eternal blade, and make its capstone impossible pre-epic.
Extra Rage from Complete Warrior is a good idea; barbarian itself gives more uses of rage only slowly.
Improved Two-Weapon Fighting can be gotten from the gloves of the balanced hand item from Magic Item Compendium. The same book has rules for adding enhancement bonuses to Dexterity to this same item without a cost penalty; obviously, Dexterity is your most important score. This build is very feat-starved, so the item makes more sense than picking up another feat. You can always pick the feat up later to replace the item.
It’s not a feat, but Twisted Charge from Complete Scoundrel will do you well.
Items
Shadow Blade only works with a select group of weapons, and you require Weapon Focus for eternal blade, so it makes the most sense to use paired short swords: they’re the best items available for dual-wielding that work with Shadow Blade. Before you get those feats, though, any combination of weapons you want to use works.
Note that Expedition to Castle Ravenloft has a sun sword, a +1 short sword that deals the damage of a bastard sword. It’s basically the sun blade without all the extra crap you don’t need; instead it costs 3,000 gp. As in, not quite 700 gp more than a +1 short sword usually would. This makes an excellent weapon to build off of; that d10 represents a +3 damage bonus over a short sword, on average. The sun blade itself is saddled with too many weak enhancements and just costs way too much money. Make sure your DM agrees that the sun sword works with Shadow Blade, too.
This doesn’t work for the OP, since he cannot use Dragon material, but for other readers: If you cannot get the sun sword or it doesn’t work with Shadow Blade, you might also consider elven lightblades, which are kind of like combo short sword/rapiers. Again, check with your DM that they are short sword enough for Shadow Blade; strict RAW, they’re not. These are exotic weapons not even remotely worth the feat you’d normally need to use them, but you’re taking a couple of levels of fighter anyway for feats, and the exoticist fighter variant from Dragon vol. 310 can get you proficiency effectively for free. Note that elven lightblades are the only possible way to have one weapon get bonuses from both elegant strikes and Shadow Blade; see the “Champion” build below for that.
Otherwise, just use short swords. The actual weapon you use is really not that important as long as it is light and works for Shadow Blade.
The gloves of the balanced hand have already been mentioned; making them double as gloves of dexterity is also an obvious priority. Also, you still do add half your Strength to damage, and your HP is on the low end, so a belt of giant strength and periapt of vitality are worthwhile, albeit at a lower priority than Dexterity. Get the best cloak of resistance generally available. Magic armor, probably angling for the fortitude or soulfire line of special abilities, is obvious. Mithral is probably your special material of choice, considering your high Dexterity.
You are going to want a speed weapon if you cannot get haste reliably cast on you. With your Dexterity, it may be difficult for your wizard to even have time to cast it before you go, and you want it for your first turn. The collision property is nice in that it multiplies on a critical hit, and various energy damage properties aren’t awful. But don’t ignore utility on your weapons; eager and warning are excellent about letting you go first, and there are weapons that improve rage or what have you, and so on. There are a lot of guides about which weapon properties you should use; this build does not have any special needs here.
Aside from that, keep up with your list of necessary magic items and peruse Bunko’s Bargain Basement for spending the rest of your money. This build does not include any built-in flight; if your alignment is flexible but your game is enforcing alignment-based rules, it’s worth being Evil just to have access to the feathered wings graft.
Barbarian 1
Your first level, your iconic level. You get rage and fast movement. You should be trading away both of these.
Rage Variant
For rage, your options are either ferocity (gain bonuses to Strength and Dexterity rather than Strength and Constitution, activate as an immediate action) or whirling frenzy (gain an extra attack). I like whirling frenzy better, but both are very solid options. Whirling frenzy will allow you to “pretend” two-weapon fighting without the feat, though.
Spiritual Totem—Lion
Complete Champion has a series of alternate class features to trade away Fast Movement for something else based on a spiritual totem. The Lion option is pounce. You need this. This is the difference from a mediocre damage build with no mobility, and a mobile damage build that is hard to pin down.
Barbarian 1/Fighter 1
Stepping aside into fighter, because you need feats. If you don’t have flaws, this is where you get Two-Weapon Fighting.
Hit-and-Run Tactics
You also take the hit-and-run tactics variant from Drow of the Underdark—you don’t need to be drow, and it allows you to add your Dexterity to damage rolls when made against flat-footed targets. That’s pretty cool, and it only costs the armor and shield proficiencies you wouldn’t use anyway. And you get +2 to Initiative, to boot.
Exoticist
This variant from Dragon vol. 310 isn’t available to the OP, but for others it may be useful. It gets you four exotic weapon proficiencies instead of all martial weapon proficiencies. You already have the latter from barbarian, so that’s no loss, and elven lightblades arguably function as short swords for the purpose of Shadow Blade. It’s a small bonus, but it’s basically free. And if you do manage to get into champion of Corellon Larethian, it works with elegant strikes, and thus the benefit is no longer anything like “small.”
Pugilist
This variant, also from Dragon vol. 310, focuses on unarmed strikes, which you won’t use much (though you could, since they are Shadow Hand weapons), but it importantly grants Improved Unarmed Strike and Endurance as free bonus feats, on top of your usual 1st-level bonus feat. It conflicts with hit-and-run tactics, and it doesn’t offer the opportunity to use elven lightblades (at least, not for free), but you need Endurance for wildrunner, so that is a pretty big deal.
Barbarian 2/Fighter 1
Uncanny dodge is nice enough. Not much to say here, class-wise.
However, it is 3rd level. Time to pick up Endurance, to qualify for wildrunner on time. Unless you went with pugilist, in which case you can actually accelerate some of your other feats. This option is best if you don’t think you’ll finish up your feats.
Barbarian 2/Fighter 2
Back to fighter, because you need feats that badly. Trap Sense is near-worthless; though Flaws can eliminate the need for fighter here, I still don’t recommend barbarian.
The feat you need here is Martial Study for a Shadow Hand maneuver. This allows you to get Hide in-class (which you’ll need for wildrunner), and you need a Shadow Hand manuever for Shadow Blade. Your options are shadow blade technique, which could easily be refluffed as a two-weapon technique, and clinging shadow strike, which gives the target a 20% chance to miss for the round after you hit.
Alternatively: Barbarian 1/Fighter 1/Ranger 2
Skills are a problem; wildrunner requires a ton of them, and barbarian and fighter are not high-skill classes. You can do well with half-decent Intelligence (eternal blade gives you a few bonuses based on it), but it’s worth noting that we’re getting Two-Weapon Fighting and Endurance—bonus feat options for Ranger 2 and 3. Thus, you can replace two levels of fighter with those two levels of ranger, which is a high-skill class (the elf substitution level in Races of the Wild even give you 8+Int!). The obvious problem is you can’t just jump to Ranger 2, so you also lose a level of barbarian as well.
We also really do want a level of fighter for hit-and-run tactics, lightblades, and/or Endurance, so trading one level of fighter rather than both, and only going to Ranger 2, is advantageous. That probably ends up being the best choice: you lose out on uncanny dodge, and an average of 3 HP (4 HP if you do take the elf substitution level, since it has d6 HD), but you retain hit-and-run tactics.
Ultimately, this works out to a lot more skills, better saves, a favored enemy, and Track and wild empathy, at the aforementioned cost of uncanny dodge, and 3 HP.
Barbarian 2/Fighter 2/Crusader 1
You gain five manuevers, a stance, and the ability to delay a small amount of damage you take for a round, gaining bonuses when you do so. Very barbarian-esque. Two of the maneuvers (or one maneuver, and the stance) need to be Devoted Spirit for eternal blade. Note that, since you’ll want to use a Shadow Hand stance in order to use Shadow Blade, your choice of stance matters only until you get that feat (which sadly won’t be for a while unless you went with pugilist).
Note that, if you like any of the 1st- or 2nd-level Stone Dragon maneuvers, now is the time to pick them up; Eternal Blade doesn’t get the discipline as an option. So definitely get mountain hammer (though its out-of-combat utility means that would be my recommendation anyway), and any others you like.
Battle leader’s charge gets a fairly sizable damage bonus (+10) on “your charge attack.” Ask your DM how pounce interacts with this; it’s completely unclear. If you cannot benefit from pounce while initiating battle leader’s charge, it’s not worth it; your other attacks should add more than 10 damage. If you can get pounce, and the +10 applies to all of those attacks, your DM is insane and this is by-far the most powerful thing you could grab right now. If I were your DM, I’d give you the +10 on the first attack, and let you have the rest as normal. Note that battle leader’s charge requires that you have some other White Raven maneuver or stance to take it.
Beyond that, I like tactical strike for a decent damage bonus if you can’t full-attack or charge, plus it lets your allies reposition, which is nice. Crusader’s strike is solid enough if you need emergency healing.
Alternatively: Barbarian 2/Fighter 2/Warblade 1
(or Barbarian 1/Fighter 1/Ranger 2/Warblade 1)
The thing about eternal blade is that it requires maneuvers from Devoted Spirit or Diamond Mind, but then learns maneuvers from Devoted Spirit, Diamond Mind, Iron Heart, or White Raven. That weird mismatch makes it very annoying for you to qualify as a warblade: that class doesn’t get Devoted Spirit, and Diamond Mind uses the Concentration skill heavily—which you can’t use while raging. You could take stance of clarity and emerald razor, which are the only two Diamond Mind maneuvers at this level that have nothing to do with Concentration. Those maneuvers aren’t bad, but probably wouldn’t be top picks for you—and to make matters worse, a 1st-level warblade only gets 3 maneuvers and 1 stance, so you only get 2 more maneuvers after those.
However, you might consider asking your DM if you could use Iron Heart and/or White Raven maneuvers to qualify for eternal blade. If you can, warblade becomes a much more serious contender: you still have access to battle leader’s charge and mountain hammer, and can also take an Iron Heart maneuver like punishing stance or wall of blades. Those are strong maneuvers (and punishing stance is very on-theme, though sadly you’ll have to ditch it for a Shadow Hand stance pretty soon for the sake of Shadow Blade), and perhaps more importantly, having an Iron Heart maneuver makes it much easier to learn appropriate-level maneuvers later when you take eternal blade.
Barbarian 2/Fighter 2/Crusader 1/Wildrunner 5
First level of wildrunner is lackluster, but you’re in! Congratulations, that’s awesome. From there, we just keep taking levels. None of the class features present options, but the primal scream feature is the big one to look for, especially the initial 2nd-level version. Hide in plain sight certainly isn’t terrible.
Your sixth-level and ninth-level feats need to be Weapon Focus (short sword is your best bet) and Martial Stance for something Shadow Hand, respectively. If you wait until 9th level, you can take assassin’s stance for +2d6 Sneak Attack damage, but the 1st-level child of shadows and thicket of blades options are both quite good as well. For that matter, the other 3rd-level stance, dance of the spider, is pretty damn cool.
Note that if your DM allows some houserules that make it possible to get into champion of Corellon Larethian, trading two levels of wildrunner for two levels of that is very much worth it.
Barbarian 2/Fighter 2/Crusader 1/Wildrunner 5/Eternal Blade 10
At eleventh level, start taking eternal blade levels instead of wildrunner levels; you have the best things from wildrunner, and eternal blade is an awesome prestige class. I suggest focusing on either Iron Heart or Devoted Spirit maneuvers, but feel free to take whatever looks cool; it will be. Avoid Diamond Mind, as it is incompatible with rage.
The feats you have left to get are Shadow Blade (finally) and Extra Rage (finally). Both of these may have been gotten much earlier if you have Flaws.
Final Build
Level |
Class |
Special |
Feat |
1st |
Barbarian |
Lion spirit totem, ferocity or whirling frenzy |
Weapon Finesse |
2nd |
Exoticist¹ |
Elven lightblade proficiency,¹ hit-n-run tactics |
Two-Weapon Fighting |
3rd |
Bar 2 |
Uncanny dodge |
Endurance |
4th |
Ftr 2 |
|
Martial Study (Shadow Hand) |
5th |
Crusader |
Maneuvers |
|
6th |
Wildrunner |
|
Martial Stance (Shadow Hand) or Weapon Focus (short sword) |
7th |
|
Primal scream |
|
8th |
|
|
|
9th |
|
|
Weapon Focus (short sword) or Martial Stance (Shadow Hand) |
10th |
|
Hide in plain sight |
|
11th |
Eternal Blade |
Blade guide, eternal training, maneuvers |
|
12th |
|
Guided strike |
Shadow Blade |
13th |
|
Armored uncanny dodge |
|
14th |
|
Eternal knowledge |
|
15th |
|
|
Extra Rage |
16th |
|
Defensive insight |
|
17th |
|
|
|
18th |
|
Tactical insight |
any |
19th |
|
|
|
20th |
|
Island in time |
|
- The exoticist variant fighter requires Dragon content and is unavailable to the querent. In that case, regular fighter is fine, elven lightblades don’t really add that much anyway. If you can get a pair of sun swords, you may not even want them.
Final Build with Flaws
Flaws dramatically improve things by allowing you to take Shadow Blade and Extra Rage much sooner.
Level |
Class |
Special |
Feat |
1st |
Barbarian |
Lion spirit totem, ferocity or whirling frenzy |
Martial Study (Shadow Hand), Martial Stance (island of blades), Shadow Blade |
2nd |
Exoticist¹ |
Elven lightblade proficiency,¹ hit-n-run tactics |
Weapon Finesse |
3rd |
Ranger |
Favored enemy |
Endurance |
4th |
|
|
Two-Weapon Fighting |
5th |
Crusader |
Maneuvers |
|
6th |
Wildrunner |
|
Extra Rage |
7th |
|
Primal scream |
|
8th |
|
|
|
9th |
|
|
Weapon Focus (short sword) |
10th |
|
Hide in plain sight |
|
11th |
Eternal Blade |
Blade guide, eternal training, maneuvers |
|
12th |
|
Guided strike |
any |
13th |
|
Armored uncanny dodge |
|
14th |
|
Eternal knowledge |
|
15th |
|
|
any |
16th |
|
Defensive insight |
|
17th |
|
|
|
18th |
|
Tactical insight |
any |
19th |
|
|
|
20th |
|
Island in time |
|
- The exoticist variant fighter requires Dragon content and is unavailable to the querent. In that case, regular fighter is fine, elven lightblades don’t really add that much anyway. If you can get a pair of sun swords, you may not even want them.
“Starting high” Champion build with Flaws
This build has two conditions before I’d consider it:
- The game is starting at a minimum of 10th level.
- The DM allows the elven lightblade to not just count as a short sword for the listed feats, but also for Shadow Blade.
It also relies on Dragon, which the OP explicitly cannot use.
Anyway, the idea is to use an elven lightblade rather than a short sword (or sun sword), and thus get Dex-to-damage from both Shadow Blade, and the champion of Correlon Larethian’s elegant strikes feature. That’s a pretty big deal, a much bigger deal that the sun sword’s bastard sword damage (+3 vs. something in the 15-17 range at 20th).
Qualifying for champion of Corellon Larethian remains inherently problematic, though. I’d very strongly consider whether or not I could do more with three feats than elegant strikes does. I probably could, particularly since this build can’t get hit-n-run tactics. Dodge, Combat Expertise, and Mounted Combat are not good feats. Combat Expertise doesn’t even work while using rage.
Fighter does help a lot here, though; the exoticist variant from Dragon vol. 310 gets Exotic Weapon Proficiency four times. This is important because we want to use an elven lightblade, but we also need proficiency in elven thinblades or courtblades for champion of Corellon Larethian.1 Which you choose, and what you do with the other two proficiencies, doesn’t much matter since this build relies heavily on those elven lightblades. A braid blade (Dungeon vol. 120) is probably the best choice just because it’s another free attack, though it won’t benefit from Shadow Blade or elegant strikes.
We can also add back that second level of fighter (or third level of ranger, if ignoring multiclass penalties; I tend to feel 4 skill points is well-worth an average 1 HP) to get another feat, since Wildrunner 3 isn’t exactly an amazing level.
Note that warblade is no longer an option; we need crusader for heavy armor proficiency. We have to skip hit-n-run tactics for the same reason: it prevents us from gaining heavy armor proficiency from multiclassing, we would have to actually take Heavy Armor Proficiency as a feat and we can’t afford to. Not that we would be caught dead in heavy armor (or equivalently, being caught in heavy armor would be a death sentence), but champion requires it so have it we must.
You can also delay Martial Stance until 9th, for the option of taking assassin’s stance, which opens up Craven (Champions of Ruin) for a large damage boost when you attack opponents in a sneak attack situation. Attacking with elegant strikes, Shadow Blade, assassin’s stance, and Craven is looking at +60 damage per attack (while dual-wielding high-crit weapons and only 2d6 of that damage doesn’t get multiplied on a crit).
By the way, in case that last line didn’t suggest it, a pair of scabbards of keen edge are good high-level investments. Improved Critical is fairly-obviously not a great choice, seeing how feat-starved we are, and keen is more expensive in the long run (keen is cheaper on a +4-equivalent weapon, but more expensive on a +5-equivalent or higher).
In general, crit-fishing is a fairly low-power strategy, but we have several things going for us here. We are already maximizing our attacks per round (TWF, pounce, whirling frenzy, speed or haste, island in time), we are already using high-crit weapons, and we already have a ton of unrolled (read: crit-multiplied) damage. When 16k becomes cheap at high levels, doubling our already-solid chances of getting a crit that’s going to hit ridiculously hard without us doing anything extra for chump change is a no-brainer.
Level |
Class |
Special |
Feat |
1st |
Barbarian |
Lion spirit totem, ferocity or whirling frenzy |
Combat Expertise, Expeditious Dodge, Weapon Finesse |
2nd |
Exoticist |
Elven lightblade proficiency |
Weapon Focus (short sword)¹ |
3rd |
Ranger |
Favored enemy |
Mounted Combat |
4th |
|
|
Two-Weapon Fighting |
5th |
|
|
Endurance |
6th |
Crusader |
Maneuvers |
Martial Study (cloak of deception or shadow jaunt) |
7th |
Wildrunner |
|
|
8th |
|
Primal scream |
|
9th |
Champion of Corellon Larethian |
|
Martial Stance (assassin’s stance) |
10th |
|
Elegant strikes |
|
11th |
Eternal Blade |
Blade guide, eternal training, maneuvers |
|
12th |
|
Guided strike |
Shadow Blade |
13th |
|
Armored uncanny dodge |
|
14th |
|
Eternal knowledge |
|
15th |
|
|
Craven? |
16th |
|
Defensive insight |
|
17th |
|
|
|
18th |
|
Tactical insight |
Extra Rage? |
19th |
|
|
|
20th |
|
Island in time |
|
- Weapon Focus (longsword) is another option, and it would pull double-duty qualifying for eternal blade, but we don’t use longswords, and getting the proficiency free gives us more latitude in when to pick up that Weapon Focus feat.
Best Answer
The too long, didn’t read here is simple: defense is not something the barbarian is ever going to do well. Trying will only hurt your offense, without appreciably improving your defense. Your survivability comes from killing things dead. Basic armor (maybe mistmail), a cloak of resistance, and invulnerable rager abilities are quite sufficient here, or at least the best you’re going to reasonably get. When you can, nightmare boots, a cloak of displacement, and things that grant you death ward, freedom of movement, and/or mind blank are worthwhile, but ultimately, don’t sweat it. Your spellcaster allies are really the ones responsible for neutralizing threats before you can kill them. Your job is to kill them.
To understand why this is the answer, and any attempt to bolster your defenses is only going to hurt you, there are a few facts of Pathfinder that you need to understand first:
Pathfinder is not a balanced game
Not every class is equally capable. Not every class is equally flexible. Some classes are very limited in what they can and cannot do. Some classes cannot do much of anything outside their specialty. Some of those classes aren’t even that good at that specialty. This is an unfortunate reality, but it is reality and you have to understand it.
People who analyze Pathfinder and its imbalances organize classes into tiers, from 1, classes that can do everything, to 5, classes that can only do one thing and even that not particularly well, or struggle doing a mish-mash of things. See What tier are the Pathfinder classes? for more details.
Barbarian is not a flexible class
Barbarians deal damage. That is what they do. They aren’t necessarily the best in the game at it, but they’re pretty good at it.
They are not good at anything else. They cannot be made to be. Attempting to do so will only throw away lots of damage potential for extremely limited skills in other fields.
That puts barbarian in tier 4. They’re pretty good at damage-dealing, and that’s a pretty important thing to be good at, so they’re better than several classes, but it still puts barbarians on the lower end here.
The best defense is a strong offense, anyway
Other classes can try to get some defenses. High-Dex can give you decent AC, magic can give you other non-AC defenses, and so on. Barbarians don’t have those options, particularly high-Strength barbarians like you (a barbarian might be able to try doing a high-Dex finesse barbarian approach, maybe, but that isn’t your character).
But ultimately, that only matters so much. Pathfinder is a very glass-cannon-y game. At low-mid levels (above 1st or 2nd or so, but below 10th to say the least), there can be some back and forth, but at high levels (and the very earliest levels), it really is rocket tag (warning: TVTropes link). Consider this analysis of what it takes to maintain relevant AC. A high-Dex character needs to spend nearly 20% of his or her wealth to maintain AC at 20th level (and to maintain it at all levels can take as much as 95%!). For a heavy-armor, low-Dex character, that number is 35% at 17th, and it isn’t even possible beyond that point.
And that’s only AC: AC is the worst defense in the game. Too many things ignore it, and most of the time it only protects you from hp damage (which only matters once you run out, while a failed saving throw often means you lose immediately). So optimal characters will fall behind in AC regardless, because it costs too much to do otherwise.
So you’re right, this is a bad houserule. There is nothing about the barbarian class that justifies nerfing it. But ultimately, it doesn’t really matter. All it really means is that you’ll start falling behind, and ignoring, your AC slightly earlier than you might otherwise—maybe. Personally, I prefer light armor most of the time, because the cost, weight, and armor check penalty of medium or heavy armor isn’t worth it to me. I would also very likely sell that ring of protection, because it’s worth a whole lot in gold pieces, while its deflection bonus to AC isn’t worth a whole lot to me (though, deflection is much better than armor or natural armor or shield).
So your best hope for survivability is to play to your strengths, and kill things dead before they get a chance to pose a threat. Throwing away lots and lots of damage potential only leaves threats more opportunities to hurt you, and you cannot trade that damage potential away for similarly-strong defenses. Those defenses simply do not exist for you to take. At very-low levels, you need to pick up the basics, and at very-high levels there are some potent options, but in between, really, just focus on killing things.
On having a strong offense
Use a two-handed weapon. Have, and use, Power Attack and Furious Focus. A furious weapon isn’t a terrible choice. Choose the Beast Totem, and get pounce at 10th level. Consider getting a mount, a lance, and Spirited Charge. Or even worship Gorum, or your setting’s equivalent, and taking his Greatsword Battler divine fighting technique—then you can take the Vital Strike line and put it to solid use (probably better than any other class).
But the goal here is simple: you charge things, and kill them. Dead and destroyed things can’t hurt you.
If you want a little more flexibility, barbarians are also pretty good at the Intimidate game; still offense, but gives you a little more ability to deal with things you can’t kill outright. Cornugon Smash is pretty solid. Intimidating Prowess, however, is an obnoxious feat tax, but you’d probably need it to go this route.
Leave protecting people to the spellcasters
That’s what they’re there for. They should be dividing foes with walls, blinding foes with darkness or clouds or just straight blinding them, hampering foes’ actions, and so on and so forth. In the face of competent spellcasting, your enemies should not be able to mount a significant offense in the first place. Battlefield control, debuffing enemies, and buffing allies are some of the best uses of magic.
Dealing damage, that is, blasting, is a really poor use of magic. They should let you deal the damage, you’re made for it and there are so many more important things they need to be doing.
Personal defenses you should have
There are certain, basic, entry-level defenses that every character should always have, even if the spellcasters are protecting people with debuffs and battlefield control. They’re just really cheap and easy to get, so there’s no reason not to.
Mundane armor that is the best in its weight class and that you have proficiency with from your class—for you, a chain shirt or leather lamellar. Mundane armor is cheap and even if armored AC is low-value, it tends to give you a big wodge of it for effectively nothing.
A +1 enhancement bonus to your armor. Mandatory for any other magic.
The highest-bonus cloak of resistance you can afford. Cloaks of resistance apply to all saves, so unlike armor they apply to a huge array of particularly-dangerous effects, and they are reasonably priced. Always get the best you can.
Beyond that, other options are mostly terrible, but there are a few things worth mentioning, especially if you can get them for mere gold instead of having to spend feats and class features on them.
Using a shield alongside a weapon.Cuts way too hard into your offense; not worth it.Higher enhancement bonuses to armor or shields.Don’t buy these; they are overpriced. Special armor properties (discussed in more detail below) are the real benefit of magic armor.Better armor due to Armor Proficiency feats.No! Feats are precious, precious things. A +2 bump to armored AC, particularly when tacked on to larger armor check penalties and slower speeds, isn’t worth very much at all.An amulet of natural armor of any kind.These cost the same as enhancement bonuses to armor, and cannot have special armor properties. Pass for the same reasons you pass on higher enhancement bonuses to armor.A ring of protection of any kind.More debatable, but ultimately these are really expensive for a relatively-small boost. Deflection bonuses are good, but the amount of gold they’re worth is better-spent elsewhere. Maybe a ring of protection +1 is OK enough; since the cost scales quadratically the +1 version isn’t too bad, and ya know, you already have one.Toughness.Toughness is a mediocre feat for a low-hp class like wizard. For a high-hp class like barbarian, it’s a complete waste of time. Your big HD, high Constitution, and bonuses from rage should cover your hp well. There are more important things to use feats on.Healing of your own.You’re a barbarian, you can’t heal people, not even yourself. Renewed Vigor and Regenerative Vigor are terrible rage powers; spending a standard action in combat is an enormous cost (you are probably only going to get 2-3 of those in a given fight), and it’s a tiny amount of healing. Let the spellcasters heal you (and help them buy wands of cure light wounds).Damage Reduction from invulnerable rager. This is pretty solid; the number isn’t terribly large but it’s much bigger than you usually see, and the cost isn’t very high (uncanny dodge is pretty good, but improved uncanny dodge is pretty niche and the regular barbarian DR is minuscule, and trap sense is garbage). You are already ahead of the game by having this.
Damage Reduction from items, feats, or other class features.Damage reduction almost-always has one of the following flaws:It also costs massively to get those small amounts—feats, rage powers, these are precious, precious things. They aren’t worth the cost. (This is especially true for an invulnerable rager, since most things won’t stack with the DR you already have. But really, even if you weren’t an invulnverable rager, you still shouldn’t get these.)
Miss chances. These are very good defenses, because they work equally-well against all opponents. Against particularly-dangerous opponents, that’s an advantage because it ignores their skills (and against not-particularly-dangerous opponents, we don’t care). A mistmail is a fine armor, for example: 3 minutes’ worth of 20% miss chance is a great deal at 2,250 gp. Paying for improved versions that have more uses per day, or simply buying more mistmails and changing between combats, is a really good choice as you level—or would be, if it weren’t for the excellent nightmare boots that you could buy instead. At higher levels, a cloak of displacement is fantastic. You can also ask your GM about possibly commissioning custom items of blur and/or mirror image for more miss chances; these arguably stack since they are for different reasons.
Immunities. The endgame, these are the real goal—effects you don’t have to worry about at all are effects that you’ll be happy to have enemies waste time trying. Death ward, freedom of movement, and mind blank are the best examples, and the latter two come in (very expensive) ring form. Death ward could be accessible from a (also likely expensive) custom magic item; speak with your GM once you get high enough in level to be considering these expenses. Fortification armor properties also fall in this category.
Special armor properties. In addition to the aforementioned fortification, armor properties are a relatively-cheap way to get defenses. Since AC ends up being too difficult to bother with, most armor properties are worth more than their equivalent enhancement cost to you. They can also offer other, more unusual features, like delving’s 10-ft. burrow speed, a rather interesting option that could allow you to bypass ambushes and get the drop on opponents by coming from unexpected angles. I recommend avoiding spell resistance, though; the numbers aren’t great and you’re just as likely to resist your ally’s buff or healing spell as you are to avoid the enemy’s attacks. Note that some of these, like stanching, may make enhancement bonuses to your armor more valuable than they’d otherwise be, but that also plays against them because they effectively cost more than they appear as you need to get otherwise-useless enhancement bonuses.