There is a reason that so many MMO's have this kind of set up in dungeons. DnD players have built parties around this idea for years. The following is the party set-up I have used up to level 25. If I find anything about this build that makes it unplayable in the late game, I will edit.
Start with a good tank:
A Warrior has amazing regeneration abilities, as well as decent damage resistance. His damage is good aswell (with cleave) so he wont be uselessly swinging for 15 damage at level 20. Level Taunt first. Get it to level 14, where the diminishing returns effect it too much to be worth leveling. There's no need to level anything but taunt until level 14. Afterwards, level Hard Skin until you have the health and resistance you need. Use this ability on the Warriors' first turn each fight. Something that some people don't realise is that you can also use this ability to heal your Warrior for a lot of health when you need it. When you have survivability down you can leave Strike or Cleave depending on whether you need more single target damage or AoE damage.
Combo with a good support:
A Cleric is the natural combo with a warrior - his Weakening ability makes all incoming damage nullified, and any damage that does come through can be healed with Restoration. With the Warrior as a tank, I rarely need to heal him and more often need to heal other party members on the rare occasion that they take damage. However, the vast majority of his turns end up in him using Smite. With Taunt healing your warrior by 26 hp per turn (before any regeneration items) it is better to mass level Weakening until you find the enemy does only 1 damage per hit. Once you have that situation, only put another point in to keep up with the increase in monster damage as the game progresses. Restoration is the second skill to level, in order to bring the other party members back to full in the rare occasion they get hit. Smite comes in last (With Circle of Healing being ignored) so that the priest has something to do in the many fights where healing is redundant. A Witch can heal with Ward that heals until that person is hit and stops 1 hit of damage while it's active, or you could use Life Drain it does damage to all enemies and heals all your party members by a certain amount. (This only works with the Halloween DLC. This message is brought to you by Ice)
(If this is your first playthrough, and you don't have the money to get all 5 characters straight away - I recommend getting cleric last, as he is the least useful early on, and has the biggest benefit later in the game when monsters begin applying bleeds and burns on your party)
Show me the damage:
Without question you should be using a Mage - his Meteor skill will 1 hit enemies early in the game and later, when you can attack 7 enemies at once, is the easiest way to deal between 300 and 500 damage in one attack (albeit spread over 7 people). Meteor is far over poewered early game, but can usually only be cast once or twice. Putting the first point into Stream can give you an extra attack sooner, and the first point but only the first point will also increase Meteor's damage. Occasionally putting more points into Stream will push you into enough mana reserve to cast an extra Meteor in a battle, but otherwise you should put all points into Meteor (by level 25, I have level 19 Meteor)
It's important that you buy the item in the shop that gives you the ability to fight 7 enemies as soon as possible, and always fight the maximum number of enemies that you can, without anybody dying. The bonus experience from killing more people in one fight is well worth the longer fights.
With all that Area of Effect damage, don't big stompy elites crush you?
Rogues are incredible at single target damage. Vanish needs to be high enough to give you about %50 critical chance (You can use items to help get there faster) By level 15 Vanish, my rogue has %55 critical chance. This should be leveled first, in order to make the next step all the more impressive. Double Strike is incredible. With such high critical chance from Vanish you end up hitting for approximately double anyone else for single target damage. Level this up as much as you can before diminishing returns make it a waste of a level. Poison gives your attacks +1 hit. When you use double strike, it accumulates and doubles. So for example, a level 10 poison increases your overall damage by 20 with double strike. If double strike crits, that damage increase is doubled.
Note:Poison is the only thing on the rogue that does not have diminishing returns after rank 10. I recommend only leveling Vanish and Double Strike to rank 10, and putting everything else into Poison. At rank 10, you have +30% critical from Vanish, which is easy to get to 50% with items. Also, at rank 10 Double Strike does 2 hits each with +5% damage, meaning you are literally doing twice as much damage than yourself when you use it.
But that's only 4 party members, Who is the fifth?
Druid is a good start, leveling Gaia's Blessing to give my Mage the extra Mana for meteor early game. Later though, the mana reserves on the Mage become insane, and Feral Rage becomes the new favourite. The damage is second only to the rogue, However, this guy is mostly for early game when your Mage needs help casting those Meteor's.
Note:The druid starts off very useful but slowly degrades in usefulness as the game goes on. The rogue just surpasses him in damage, and the Cleric can do as much damage with Smite, because of diminishing returns on Feral Rage as it levels.
Other Strategies Edit
You can get through a lot of the game fine with only 4 members; you might want to only use 4 until you unlock another guy, depending on what you want or need to fill out your team. If you find your Warrior isn't pulling enough threat or is dying too much, a Barbarian does the most damage out of the tanks and get a lot of life back from life-steal. Also, a Knight has built in life-steal, damage reduction, and threat pull for a superb all-around tank. He may need a little healing, at least until his critical chance and lifesteal gets high, but is the best all-rounder of the tanks.
If you want more single-target damage, then the Hunter is similar to a rogue because he gets high damage and high critical chance. In addition, he has one AoE skill for the large fights, and he can make a foe Bleed, which is very good for big bosses. He usually goes last in exchange for higher base attack than the rogue, but the rogue will out-damage him with Double Strike.
Another option is the Necromancer, who increases the lifesteal and critical chance of himself, the rogue, and the warrior; just make sure all 3 are next to each other. In addition, he can give himself mana by attacking, and (most importantly) can bring downed allies back to life for the remainder of the fight. This means that losing your only tank doesn't mean you lost the fight, as you can pull him back up to continue taking hits for your damage characters.
If you want to more AoE damage, then my personal recommendation is the Shaman. He not only has a skill that hits everyone in the fight for damage of time, not only does he have a powerful attack that hits 3 people, but he has a skill that raises the magic stat of 3 people on your team. Raising the magic stat also increases mana, it can target himself, the mana restoration can be used repeatedly (the magic buff only stacks once) and it gives him over 3 times as much mana as it costs him. The shaman is the perfect way to never run out of mana ever again.
On a team like this, the only reason to choose the Bard is if you are having a lot of trouble with AoE damage. The Bard has an AoE heal, Harmonic Movement a healing skill that targets himself/herself and one other person (It can be used on himself/herself twice), a damage buff for the entire party and Dissonance a AoE spell that hits the entire enemy party. However, the AoE attack is rather weak, you already have a healer, and only 2/3 of your party members would benefit from her attack steroid.
Alternative Starter Party
Little Brother Paladin: All the Paladin's skills are useful, but the key here is to use Holy Shield to reduce damage and Leader Strike to attract attention. Little Brother is good here for the initiative bonus. As you develop this character, put ranks into Holy Shield, Leader Strike and Devotion evenly (in that order), until you have 4-5 ranks in Holy Shield, after which build up Leader Strike to 6 ranks and Devotion to 10 ranks. You can then put up to 10 points to Flash Heal, and work on Devotion some more.
ET Druid: Regeneration, Gaia's Blessing and Feral Rage are your key skills. Hibernate would be good too, except that it's rarely useful when you need it most. Put 1 point into each of the above skills, in the order listed. Then focus on building up Regeneration and Gaia's Blessing until you have 10 points in each. Use Regeneration as you main source of healing for the party, and Gaia's Blessing to regain MP.
When you can afford it, add the following:
Hipster Mage (only work on Meteor, with 1 point in Fireball), Jock Rogue (Vanish, Double Strike 10 points, then Poison) and Hynx Cleric (mainly Weakening, with some Holy Strike and Restoration).
The Paladin tanks, the Mage and Rogue are your main damage dealers, with the Druid providing key support (healing and MP restoration) and the Cleric disabling enemies (weakening). Large groups of enemies may take a while to deal with, since you have only one character able to attack multiple enemies at once, but single foes won't last long.
AoE-Single Target-Support Combination
If you play with only 3 characters- initially or throughout the game by choice, a decent template for doing damage synergises an AoE member, a single target damage member and a support member. Including a tank soaks up enemies' attacks, but does not add enough damage or offer enough general benefits to be worthwhile. For AoE the Mage with meteor is the "only" option, similarly the Rogue using double strike for single target damage. After initially using Cleric I found Druid to be a much more versatile support class, using all skills but primarily regenerate and Gaia's blessing.
The roles of the first two are self explanatory. One or the other will be more effective depending on the number and type of enemies. The support role using Druid will be to regen the team's health according to threat, regen MP to perpetuate your magic attacks, do damage with feral rage to speed up easier battles, and occasionally use hibernate to slow down harder ones. The Cleric's strategy would be to run weakening on the enemy party - very very effective, but a bit boring to juggle all the time with more than 3 monsters. The Cleric is also unable to regen magic, so longer battles can sometimes grind to a halt when MP run out (enchanted items mitigate this problem).
Sensible character choices would be ET Mage for the MP, Hynx Druid for extended regenerate/bleed/sleep and possibly Jock Rogue for the attack although with the highest threat in the party, Woofie or Rocker could be good for taking damage. Even Ms. Goldberry would be a good call as HP and MP Steal are very useful. You may consider substituting Flowers for Mage or Rogue because there are just so many dice rolls in the game.
Once you've unlocked the other characters and classes available in the game, I've found the following party to be very effective, completing the main quest line in 345 game days:
Saulo Paladin, Ronaldo Bard, Hipster Mage, Flowers Shaman and Hynx Cleric.
The Bard is good for Octavarium and Harmonic Movement, with Dissonance being an acceptable multi-target attack. The Shaman mainly uses Static Field to regenerate MP, but Hurricane is an excellent multi-target, multi-round attack which should not be overlooked. Used properly, this group can end most battles with nearly full HP and MP, even after taking lots of damage and using powerful attacks like Meteor every round.
The main idea of this party combo is to have all of the members working together in order to improve there combat effectiveness. With all the buffs on everyone they can have increased lifesteal, attack damage, critical chance, as well as magic power.
Seats from left to right: With this seating the buffs will be placed on the people who benefit the most from the abilities which are 3 seat AOE abilities.
Shaman: He has great AOE abilities and damage over time which will help to add extra damage or to focus a high priority target by stacking multiple bleed effects. His static field will also buff all magic users or to keep your party supplies with MP.
Bard: The heal over time the bard offers is powerful if leveled and will allow the bard to focus on other things as well as healing. His powercord ability is very useful which increases all physical damage your party deals making your damage output overall improved. Plus can add some AOE damage.
Necromancer: Can assist by doing high damage over time and reduces there resistances making all damage increased to your target which helps nuking down any harder enemies. His help from below increases life steal and critical damage making your attacks that much more powerful and adding some more survivalness.
Knight: His general physical resistance makes him quite tanky along with lifesteal and critical damage which will be increased by the other members of the party making all of his abilities to do damage and survive even higher than normal. The knight becomes a beast when using defensive strike, frontline, along with his natural lifesteal and critical chance which is improved by the other members and heal over time from the bard makes the knight almost unstoppable.
Hunter: His ability to improve his critical chance and attack damage allows him to deal massive focused damage as well as he has a high bleed effect adding to the parties nuke abilities or can go more for AOE with his volley ability. All of this is once again increased by the other members of the party.
Power Leveling Party
Another composition which takes advantage of specialized characters and allows the party to continuously fight large groups of enemies. Purchase a Rogue, Cleric, Knight, Mage, and Shaman in that order, as soon as you can. Also invest in a table item which regenerates MP.
Rogue (Gui): Split points between Double Strike and Poison. His mana regeneration and mana steal allow him to double-strike every turn. Place 1 point into Concussive Strike for problematic fights, but ignore Vanish. Instead, boost critical chance with all four item slots, which will bring him to ~40-50%
Cleric (Ms. Goldberry): Split points between Smite and Restoration. Once the party begins to encounter enemies with AOE attacks, start levelling Circle of Healing enough to keep your characters alive. Equip her with MP Regeneration items, such as the One/Two/Three/Four Ring.
Knight (Hugo): Place 3-5 points in Defensive Strike and Dragon Blood. Then put everything into Combat Skill. His character perk, coupled with Combat Skill, will give him 50-60% critical chance (100% when using Defensive Strike). Equip with Full Plate Rings and other defensive items. This class can be replaced with Paladin or Barbarian if desired.
Mage (Any): Place all points into Meteor, with 1-5 in Stream as needed, and 1 point in Fireball. Use items to boost his magic stat as high as possible.
Shaman (Any character with + Initiative): Split points evenly between Static Field and Hurricane, with 1 point in Vine Trap. Equip him with magic-boosting items and a few MP regeneration items.
Order your party as Rogue, Mage, Shaman, Cleric, Knight. This party composition allows you to battle mobs of 7 enemies continuously, with very high damage output and the ability to recover both HP and MP as battles progress. The Mage will use Meteor continuously against mobs, and stack Fireball burns against single targets. The Rogue will continuously use either Double Strike for DPS or Concussive Strike to stun-lock as the situation warrants. These two characters are your primary damage output. The Shaman, in the centre lane, will use Hurricane three times, followed by Static Field. This ensures that your characters never run out of MP, and the Shaman's Hurricane deals as much damage as Meteor once the bleed effect takes place. The Shaman will also stack Vine Trap bleeds against singular foes. The Cleric will Smite when there are no characters to heal, and use Restoration or Circle of Healing when there are. Her damage is decent in the early game, but quickly drops off. She is your only healing character, so use her to keep your characters at full health at all times. The Knight is your tank. He will continuously use Defensive Strike for decent critical damage and protection, and Dragon Blood when he needs HP. Without debuffs, the Knight's high critical rate will allow him to HP steal enough to stay alive in most fights.
The stacking of Meteor and Hurricane allows the party to engage mobs of 7 enemies as easily as fighting elite mobs. This increases the EXP rate and decreases need for grinding. It also splits the party's damage across many types: Physical is represented by Rogue, Knight, and Shaman's Hurricane bleed. The Mage deals very large amounts of magical Meteor damage, and the Druid deals heavy Nature damage through Hurricane. When the last enemies are close to death, use the Shaman's Static Field and the Cleric's heals as much as possible to top off the party's HP and MP bars in preparation for the next fight.
Hourglass is very important to this strategy, extending the duration of Hurricane, Vine Trap, Fireball, Concussive Strike, and Defensive Strike, and increasing damage output significantly. All items which increase HP and MP Steal or Regeneration are highly useful. Miniatures are also useful, sparing the single skill points for Rogue's Concussive Strike, Mage's Fireball, and Shaman's Vine Trap.
Here write battle stratigies that you have used to defeat enemies.
Using the Tank;Healer;DPS set up as above:
Rogue uses Vanish
Warrior Uses Hard Skin (Before you have Hard Skin, just attack)
Druid Uses Feral Rage
Mage uses Meteor (Mage will always use meteor or normal attacks, so I will omit him from here onwards)
Cleric uses Weakening, making sure to hit the most / the most powerful monsters.
Rogue uses Double Strike (Like the mage, the rogue will always be using double strike from here on out, as leveling vanish first means you get 15 turns of the critical effect.)
Warrior uses Cleave / Strike (Or regular attack if you haven't got this yet)
Druid uses Gaia's Blessing (The idea is to make sure the mage can always use Meteor. If the mage doesn't need mana, keep using Feral Rage)
Cleric uses Weakening, cycling between monsters to hit up to 6 monsters in total over two turns. Make sure to cycle every other turn as the Weakening effect only lasts 2 turns. He will rarely have to heal anyone, but if he does, prioritise healing over casting weakness.
By now, even in the toughest battles, you are beginning to kill enemies. Focus down people one at a time with the rogue's Double Strike and other people's attacks until they are low enough for the bleed from Feral Rage or the AoE from Meteor to finish them off.
In all honesty, most fights wont need this much, just a few Meteors and some auto attacks will be enough. I rarely need to follow this guide so much as use it as a frame for my fighting style.
Using Shaman Necro Rogue Barbarian Cleric (Right to Left)
in turn 1: Shaman uses Vine Trap if dealing with single targets, or Hurricane if a larger group. If anyone is low on mana, Static Field comes first. This really could be any one you want.
Necro uses Help from Below on the rogue
Rogue uses Vanish if Help from Below is low level. If not, Double Strike. (Rogue uses Double Strike for the rest of the fight unless stun-locking is required with Concussion Blow)
Zerker goes Berserk!
Cleric cycles Weakening on packs of enemies. I would get Hynx and the hourglass items for longer duration. If needed, the Cleric can provide Divine damage or healing.
in turn 2: Shaman continues doing what they do best
Necro continues using Help from Below or any other damage spells. When you are finished using spells, give him a Red Pepper. Energy Drain plus Help from Below and good atk damage is just to good. Use Ronaldo if you want a HUGE affect. You could even have him as a third, lesser tank due to the Life Steal.
The rest of the time you should use offensive skills unless needed otherwise. The enemies should be pretty much dead in the next couple turns.