Well, I've been hanging out in #FFT on Effnet (I go by Galaxia, Endymion, or PenPen, usually Galaxia), and a lot of people have had questions about the deep dungeon. This answers some of these and is a guide for it.

Q: How do you get there?
A: Heh don't quite remember, its a rumor you can hear in a bar of a southern town. I think you have to be at least near the end of the game. You might have to have gotten Cloud.

Q: What's the point of it?
A: A ton of good EQ and the Zodiac summon spell.

Q: Does it affect the game if you beat it?
A: Not that I know of. I haven't beaten it again since I completed the dungeon so maybe you DO get a different ending. If anyone knows, mail me (address at top and bottom of this document).

Q: How do I get Zodiac?
A: Skip to the Floor 10 section of this guide.

Q: Do you know any other cool guides?
A: Prima's Official Strategy Guide is great! Except it left out a few things (which I on the other hand DID include), and they completely screwed up the item list for Floor 10.

Q: You mind if I mail you later with questions?
A: Not really. But I'm incredibly lazy and may ignore your letter till I feel like answering it, which might take a day or two (well, lazy or not home, or a combination thereof).

Q: How do you pick up the items in the Deep Dungeon?
A: Equip the Move-Find Item skill, available from the Chemist class. When you walk over the appropriate square, instead of setting off a trap, you will find an item. You will either find a Phoenix Down or the real item. Your chance is 100% minus 1% per bravery of the character, I think. So you want your searchers to have really low bravery, unless you want to miss the best EQ in the game!

The Wonderful World of Catching

There's an ability called Catch, a thief skill, which allows you, for the low, low price of 200 JP, to catch enemy thrown items. If you haven't noticed, Ninjas throw stuff. In fact, once they get strong, they throw cool stuff. REALLY cool stuff (by the way you'll run into large groups of ninjas an samurais on Floor 9, and you can block off their walking rout so all they can do is sit there and chuck stuff at you). As they get into the 90s they will begin to throw Defenders, Kogo Knives, Excaliburs, Javelins, and, most importantly, CHAOS BLADES! These are the best weapons in the entire game. They have a whopping attack power of 40, while casting regen on the wielder and randomly petrifying (instant death) their target. Learn to make these your best friends. Whatever people say about math mages being better, nothing matches a knight with 700hps doing 1998 damage per round!

Deep Dungeon Floor-Item Breakdowns Is it just me or does that sound wierd? Anyhow... Here's how this works. First of all, I'll describe items if they're never before seen.

As for locations, I'll list all the items and the (X,Y) coordinates of them. The only problem is I can't draw with text so, you have to figure out which corner the origin (0,0) is in. And there is a 0 column, so the corner of the map would be (0,0), not (1,1). Got it? Hope I didn't confuse you. I'm one of those guys who doesn't make much sense and confuses everyone... anyhow, I digress. Here.

Floor 1 - Nogias
(0,6) Elixir (full hp/mp item)
(9,4) Kiyomori (don't worry about it they're buyable)
(2,2) Blaze Gun (casts random ice spells)
(0,9) Glacier Gun (casts random fire spells)

Floor 2 - Terminate
(0,4) Elixir
(10,6) Elixir
(7,2) Blood Sword (crap sword but drains hp when you hit)
(1,8) Save the Queen (same as the one you got earlier with a character)

Floor 3 - Delta
(0,2) Elixir
(12,5) Elixir
(6,7) Yoichi Bow (pretty decent bow, but you should know by now, archers suck)
(9,1) Mace of Zeus (6 weapon power, 15 phys evade, +2at +1ma, my favorite staff)

Floor 4 - Valkyries
(12,8) Elixir
(4,2) Faith Rod (gee, why would a rod that makes your faith 100 be useful... *evilgrin*)
(5,0) Kaiser Plate (46phys evade, 20magic evade, strengthens your fire ice and lightning)
(5,1) Fairy Harp (nice harp if you actually use bards, randomly charms!)

Floor 5 - Mlapan
(0,0) Elixir
(6,11) Elixir
(0,11) Iga Knife (second best ninja knife in game)
(2,8) Excalibur (same as Orlandu's)

Floor 6 - Tiger
(10,9) Elixir
(9,8) Cursed Ring
(9,9) Secret Clothes
(10,8) Blast Gun

Floor 7 - Bridge
(4,4) Elixir
(4,14) Elixir
(4,10) Sage Staff (strongest staff but no magic bonuses so i like zeus better)
(4,12) Koga Knife (best ninja knife)

loor 8 - Voyage
(2,10) Elixir
(3,8) Ragnarok (weapon power of 24, casts shell on wielder, second best sword)
(6,7) Robe of Lords (100hp, 80mp, AT +2, MA+1, Protect on wearer, it's THE robe)
(8,6) Perseus Bow (best bow in the game)

Floor 9 - Horror (This is where to fight Ninjas)
(1,3) Elixir
(2,0) Maximillian (200hp armor, the best armor)
(8,4) Grand Helmet (150hp, protection from dark and sleep)
(8,5) Venetian Shield (50phys evade, 25magic evade, half damage from fire/ice/lightning)

Floor 10 - End This floor, contrary to popular belief, has NO ITEMS. Trust me, I walked over EVERY SINGLE SQUARE of it before and after killing Serpentarius (I assure you, that took a LONG time). This level is just the home of Serpentarius. He's pretty difficult for one reason: You DON'T want to kill him. At least not until he teaches you Zodiac. And therein lies the difficulty (and why this level took me 5 hours). Hopefully, my advice will keep your trip to him below 2.

Getting Zodiac in Five Much-Harder-Than-They-Sound Steps

Requirements for learning it:
-Learner must be a summoner.
-Learner must get hit with Zodiac and SURVIVE.
-Learner cannot use the doubt faith spell to survive
-Learner still only gets about a 30% chance of learning it even if you do all this.

Directions:

First, give two knights the two sword skill and some Excaliburs or Save the Queens or Ragnaroks or Chaos Blades. Just get rid of the Apandas and try not to get too close.

Second, see if you can weaken the friendly Apanda so he's at critical, so that he sits and cowers in the corner. Otherwise he might kill Serpentarius when you're not looking.

Third, get a summoner's Faith LOW (20 or less). By doing this, Zodiac will cause much less damage to you. (100 instead of 650). Use the Talk Skill, Solution.

Fourth, get someone with lots of hps out over by Serpentarius, and get the summoner far away. He will, of course, use whatever does the most damage to the easiest target (and hopefully cast Zodiac on the tough guy).

Fifth, quickly move your characters together so that the summoner is caught in the blast radius. (The reason for steps 4 and 5 is that if he attacks someone with low faith, he will use a non-magical attack called Midgar Swarm instead for 400 hps)

If you're lucky, you'll learn Zodiac. It costs 99 mp and takes as long as Bahamut, but if your Faith is good, it will do 999 damage to a 4 square radius. Quick charge makes this even further useful. One warning in this fight, if someone with 20 or less faith dies, they become VERY inconvenient to raise or heal, so try to keep the summoner safe.

I guess that's all I have to say about the Deep Dungeon! I may do a more comprehensive FAQ of this game at some point, but most likely I'll be too busy or too lazy. If you need help, mail me at endymion@linex.com. I prefer to answer difficult questions, or opinions, and I've been known to get annoyed when people ask me stuff they could have gotten from reading a FAQ if they weren't too lazy to look it up.

Credits:

Thanks to Prima for their helpful (although sometimes inaccurate) Strategy Guide.