On the Dual Job system

Edit#1 (24 Sep 2013): 
- Dual Job once chosen cannot be changed. 
- Element Memory added to List of Unavailable skills.

Edit#2 (26 Sep 2013): 
- More skills with level caps (Shaman, Ranger, Merchant)

The Dual Job system that many of our friends have been yearning for is finally out! This post is to help give an idea how the system is like.

Note that unlike most of my guides, I don't speak from personal experience here; the information found in this post comes from my attempts to translate what's found in the official site. As such, I can't guarantee that every bit of info here is 100% accurate, though I will strive to be as close to that as I can =3

For those who can read Nihongo, you can refer to this page: http://econline.gungho.jp/gamedata/system/dualjobsystem.html

1. Requirements:

You have to be a level 110/50 Reborn character in order to be eligible for Dual Job.

To apply for Dual Job, speak to the NPC フレイズ (Phrase?) found at Infinite Corridor B41 (the blonde Forcemaster with short hair and red eyes). You will be given a trial to overcome (official source gives no details on what sort of trial, but most likely it's similar to the Chronicle Job armor quests) before you can unlock the Dual Job system.

2. Basics:

• On Class and Job level: 

Almost all Classes, even your existing Class (e.g. Gladiator/Swordsman), can be chosen as your Dual Job. The only exception is the Novice/Joker (Joker/Novice, no; Joker/Anything else, yes) and of course DEM. The maximum job level for your Dual Job is 110.

If you're not satisfied with your current Dual, you can change it by speaking to a certain NPC in IC B41. Also, after clearing a certain event, you will be able to get Tomes of Conversion (転換の書) from a certain NPC in Uptown that provides the same function.

However, the official site doesn't say if changing your Dual will reset your Dual Job level or not. Chances are you'll have to re-level your Dual after a change so please take this into consideration.

You can't change your Dual Job so think carefully about what you really want for your character.

• On Stats:

You will receive bonuses to specific stats based on your Dual. For example, Wizard as Dual will give you bonuses to DEX, MAG and INT.

• On Equipment:

You will be able to equip everything available to your Dual's Chronicle Job. For example, if your Dual Job is the Warlock, you'll be able to use 1H Axes in addition to Staves and Daggers. And of course, you'll be able to wear the Chronicle armors for both your Main and Dual Jobs.

• Others

Note that non-Merchants won't have access to the Vending options even if they choose the Merchant as their Dual Job.

3. On Skills:

The Dual Job skill system works a bit differently compared to the Main's; in fact it's pretty much like an extended version of the Joint Job system. Instead of allocating skill points to learn or level a skill, skills and their subsequent levels are automatically unlocked once you reach the required job level. For example, for Sword Delay Cancel, level 1 is available at J.Lvl 35, level 2 at J.Lvl 40 and level 3 at J.Lvl 45. So to master SDC, your job level must be at least 45. Also, as you can see here, the level at which each skill is initially available for the Dual Job is different from its counterpart in the Main Jobs.

You can select up to 10 skills from your Dual Job. To choose a skill, double-click or drag it to the list of selected skills (indicated by the red box as shown in the above image).

To remove a skill from the list, simply double-click on it. Before you can do this though, you need to speak to a certain NPC in IC B41 first. Also, after clearing a certain event, you will be able to get Tomes of Conversion (転換の書) from a certain NPC in Uptown that provides the same function.

To use the skills chosen in the Dual Job window, go to the Skill Window (CTRL + S) and look for the skill you want from the "Dual (デュアル)" tab.

Note that some skills can't be learnt through Dual Job and there are also others that are restricted to a lower max skill level.

• Skills that can't be learnt through Dual Job

1. All Spirit (OOの魂, Expert j30) skills
2. All Communion skills
3. All Chronicle j10 skills (Gladiator, Astralist, Stryder...)
4. All Chronicle j50 skills
5. All Scroll Making skills (O属性スクロール作成, Sage j3~12)
6. Big Spender Warehouse (お得意様倉庫, Backpackers' Base j30)
7. Soul Protect (ソウルプロテクト, Guardian j25)
8. Cloaking (クローキング, Assassin j20)
9. Evacuate (見切り, Eraser j25)
10. Merciless Shadow (マーシレスシャドウ, Eraser j35)
11. Shadow Sewing (影縫い, Eraser j40)
12. Invisible (インビジブル, Sorcerer j8)
13. Element Memory (エレメントメモリー, Astralist j47)
14. Holy Feather orz
15. Sacred Embrace orz
16. Mega Dark Blaze (メガダークブレイズ, Soultaker j3)
17. Inherent Weapon Enhancement (潜在・武器強化, Maestro j13)
18. Inherent Armor Enhancement (潜在・防具強化, Harvest j13)
19. Equip Fusion (武具融合, Harvest j3)
20. Equip De-fusion (武具融合分解, Harvest j23)
21. Negative Harvest (ネガティブハーヴェスト, Harvest j20)
22. Treasure Scanning (トレジャースキャンニング, Treasure Hunter j20)
23. Connection (コネクション, Trader j33)

• Skills with lowered max levels

1. All Chronicle Weapon Masteries (Gladiator, Guardian, Eraser, Hawkeye, Soultaker j3): lv 5 -> 3
2. All Repair Kit Making skills: lv 5 -> 3
3. Killing Zone (殺界, Blademaster j38): lv 5 -> 2
4. Solid Body (ソリッドボディ, Bounty Hunter j34): lv 5 -> 1
5. Ekviry (エクヴィリー, Gladiator j20): lv 5 -> 3
6. Godspeed Slash (神速斬り, Gladiator j45): lv 5 -> 3
7. Sword Sage (剣聖, Gladiator j47): lv 5 -> 3
8. Blood Absorb (ブラッドアブソーブ, Darkstalker j43): lv 5 -> 3
9. Reflect Shield (リフレクトシールド, Guardian j20): lv 5 -> 1
10. Spiral Spear (スパイラルスピア, Guardian j35): lv 5 -> 3
11. Blocking (ブロッキング, Guardian, j45): lv 5 -> 3
12. Fortress Circle (フォートレスサークル, Guardian j47): lv 5 -> 2
13. Efficus (エフィカス, Eraser j20): lv 5 -> 1
14. Tempest Shot (テンペストショット, Hawkeye j35): lv 5 -> 3
15. Search Weak Point (サーチウィークポイント, Hawkeye j 45): lv 5 -> 3
16. Solid Aura (ソリッドオーラ, Sorcerer j10): lv 5 -> 4
17. Divine Barrier (ディバインバリア, Sorcerer j47): lv 5 -> 3
18. Force Shield (フォースシールド, Forcemaster j20): lv 5 -> 2
19. Barrier Shield (バリアシールド, Forcemaster j25): lv 5 -> 3
20. Zen (ゼン, Elementaler j30): lv 5 -> 3
21. Earth Aura (アースオーラ, Enchanter j27): lv 3 -> 2
22. Water Aura (ウォーターオーラ, Enchanter j28): lv 3 -> 2
23. Delay Out (ディレイアウト, Astralist j3): lv 5 -> 1
24. Wind Explosion (ウインドエクスプロージョン, Astralist j45): lv 5 -> 2
25. Prana (プラーナ, Druid j47): lv 5 -> 1
26. Recovery (リカバリー, Cardinal j40): lv 5 -> 1
27. Divine Breaker (ディバインブレーカー, Cardinal j45): lv 5 -> 1
28. Salvation (サルベイション, Cardinal j47): lv 5 -> 1
29. Soul Sacrifice (ソウルサクリファイス, Cabalist j50): lv 3 -> 2
30. Evil Soul (イビルソウル, Necromancer j40): lv 5 -> 3
31. Flame Heart (フレイムハート, Blacksmith j50): lv 5 -> 3
32. Twisted Plant (ツイステッドプラント, Harvest j40): lv 5 -> 2
33. Harvest Master (ハーヴェストマスター, Harvest j45): lv 5 -> 4
34. Mistletoe Shot (ヤドリギショット, Harvest j47): lv 5 -> 3
35. Stamina Take (スタミナテイク, Explorer j47): lv 5 -> 1
36. Good Luck (強運, Treasure Hunter, Gambler j14): lv 5 -> 3
37. Vigilance (警戒, Treasure Hunter j40): lv 5 -> 4
38. Book of Knowledge (知識の書, Stryder j40): lv 5 -> 3
39. Pillage Act (ピレッジアクト, Stryder j47): lv 5 -> 3)
40. Price Hike (プライスハイク, Merchant j17): lv 10 -> 5
41. Drop Burst (ドロップバースト, Trader j50): lv 3 -> 2
42. Bad Luck (悪運, Gambler j27): lv 5 -> 3
43. Damage Marking (ダメージマーキング, Royal Dealer j13): lv 5 -> 4
44. Bag Master (鞄の達人, Royal Dealer j45): lv 3 -> 1

You check the levels required for the skills and their levels from the link below. Just click on the class you're interested in:
http://econline.gungho.jp/gamedata/system/dualjobsystem.html#skillist