The Levels of LAD plus Attempt to Walkthrough

Lad has 14 levels, each has its own way of finishing, its own peculiarities... I'll list these here. You can find maps of the dungeon in your game file. They're the 000, 001, 002 etc. files you can find in the directory where you keep your game. You can open these using Notepad. They're programmed in ASCII, so it's quite easy to decipher them.

Lvl 0 The Dungeon Of Compuserve
This is where you begin your game. After you started up, your cursor will point to the character that's you, and your character will start to dance. Whee!
This level has one trap door, a few monsters, all goblins, and all buildings. This is also the only level where you can save a game.

Lvl 1 Level of Certain Discomfort
The first level will treat you to one trap door, goblins, small bats and orcs. You may also find leather armors, walking sticks, small knives, rings, and some minor magic potions and scrolls. You may also find a fountain.
Level one is the smallest level. I find it quite convenient to try out potions here, just in case you might have a forgetfulness drink.

Lvl 2 Level of Doors
This level has 3 hidden doors. The first one is in the second row of the top. to the far right of the level before the secret area. The other two are placed next to each other, on the bottom row at the far right. A Brain Limpet is a fixed monster here. Beware, he may cost you your intelligence.
There are more fixed monsters. One is in the hidden area, in front of the downgoing stairs. That's a Rabid Snake, who will probably poison you. There are also 2 Giant Banana Slugs in the tiny chamber, directly left to the double secret doors. Do not enter! Unless you are ethereal, or in a high level, there's no beating these monsters. They can only be harmed by spells, but... they guard a Sun Sword, an awesome weapon.Other monsters you may encounter are goblins, orcs, hobgoblins, large bats and small ghosts. Small ghosts can eat your strength, so watch it!
There are also a few trap doors and dart traps... and a teleportation trap.

Lvl 3 Level of Doom
This level is the first true maze. It has a large amount of small chambers, paths, and fixed traps. Most of these are dart traps. There's one "dart room" with a lot of these, but you can dodge them. The staircase to the top is at the bottom left.
There's a few fixed monsters to beware: the Giant Sap Sucker in a small room in the top middle, the Mad Archer in the small alley in the middle right, and a Dumb Ass in the lower middle, a bit to the right. All these are more or less locked away, so you don't have to fight them.

Lvl 4 Level of Keys
This one also involves a lot of unnecessary walking. The stairs down are at the bottom left, behind a key with a platinum lock. The platinum key can be found at the high middle right, behind a door with a golden lock. The golden key can be found at the bottom left, behind a silver lock. The silver key can be found at the high left, behind a tightly closed door, and defended by a Gelatinous Cube. These won't harm you much, but can only be killed by spells. In this level, they take about 2 magic missiles. The stairs up are in the middle, and will need a lot of searching. They're also guarded by a Gelatinous Cube.
Also beware of Rust Monsters, Poltergeists, Hobgoblins, Eyeballs and Tracking Hounds. And a nasty little Leprechaun.

Lvl 5 Level of Attraction
The 5th level has little walls in the middle, they form a sort of +-sign. This level has also a Target Training. Not much to beware for, really.

Lvl 6 Level of No Keys Up
Level 6 begins rather curiously. You seem to be trapped in a small segment, which is an alley around a square, in which you may find the stairs up. These stairs are behind 3 locked doors, and the keys are nowhere to be found...
Tiptoe around. There's some 7 secret doors. You'll need to go to level 7 for the keys to get up, though... Unless you know the Fireball or Lightning Bolt spell, in that case you can try to blast the doors.

Lvl 7 Level of Keys Up
This level has an interesting design, in which it's easy to find your way. There's about 8 keys to be found here, and only 3 of them will go into the locks at the top. You won't need the rest, so trash'em.

Lvl 8 Level of Intermission
Even though its name is cute and easy-sounding, you will find it hard to get around in this little sucker. This level has invisible walls, and invisible enemies. The Invisible Stalker comes here to haunt you. The image of an IS is a black square. You can only see him if he walks over a building.
This level also has a bank, a college, and a pawn shop. You'll have a hard time finding them. Also, the staircases are positioned at random, so finding your way out can be a hard task.

Lvl 9 Level of Malevolence
In this level, you can find a lot of interesting monsters. There's the Enchantress, the Rings-reference Gollum, the Living Dead, the Giant Slime... There's one secret door between you and the down staircase: in the 3rd door you encounter when you're coming from the top left, go to the bottom of the room, then the far left. Right down you, there's the secret door.

Lvl 10 Level of Floop

This level has the first Wraith Daemon. It will come directly after you the minute you step into the level. It can only be destroyed using the Magic Fire or Annihilate Monsters spell. So watch every step you make carefully; if the daemon hits you, you're very nearly or very actually dead.
You can also find White Dragons and Hell Hounds which can harm you from a distance. The Missile Defense power protects you from their missiles

Lvl 11 Zig Zag
This level with the interesting pattern is rather easy to get through. There's 6 secret doors which will save you a lot of walking.
You begin at the top right, from there walk all the way down, two steps to the right, bump into the wall. There's the door. Open it, keep on walking in the same direction. You'll find 4 more doors. There's another secret door, a little higher (about 5 spaces) from the bottom, on the right wall.

Lvl 12 Level of Clarity
This is another nicety with invisible walls, and monsters that are next to impossible to beat. My tactic is to get Missile Defense, Etherealness, and read a Magic Mapping scroll. Then I run for the staircase down.

Lvl 13 Level of Large
Level 13 is indeed a very, very large level. You may need to close down some screens once you get here. I haven't been here too often myself, and when I get here, it never takes me too long to get killed. You're looking for an object named Ring of Winning here. I've found it twice this far, and managed to drag it home once. The tactics are pretty much the same for level 12: you need a scroll of Magic Mapping, etherealness, the spells Magic Fire and Annihilate Monsters, all the luck in the world and your undivided attention. Get ethereal and Missile Defense, click on the Magic Mapping scroll, look for rings (there's lots of them), find a Ring of Winning (there's more than one), race to the stairs.

Attempt to Walkthrough

Making a walkthrough of LAD is impossible, as every time you play a dungeon, it's different. There's a large luck-element in this game, as falling through traps or stepping into teleportation traps usually means death awaits you. Since most traps are randomly placed, well...
Provided everything goes well, the gameplay should be a little like this:
You begin in DLV 0, equipped with your walking stick and your leather armor. You can see a number of buildings, some piles of gold, and a few goblins.
Slay the goblins, collect all the gold, deposit the gold at the bank, and go down the stairs. Explore DLV 1, but step on as little places as possible to prevent you from falling into a trap. When you're done, try all rings, potions, scrolls you may have found in this order. Then go back to DLV0. There, un-equip your weapon and armor, sell all excess items (but keep a spare weapon and armor), take one or two classes at the college, visit target training and go to DLV 2. Re-equip your weaponry, explore the level except for the secret area, go back to DLV 1, un-equip, to DLV 0, sell excess items, visit target training, take more classes, explore the rest of level 2, go back up again for target training... Keep on bouncing back and forth again, exploring a little more every time you go down. As you are walking through level 3, either your weapon, or your armor, or perhaps both will give in. Hopefully you have enough gold pieces to buy a little weapon at the shop, they won't break so easily.
When you learn the spell of fireball, use it to disintegrate walls at convenient places. That will save you a lot of walking.
As you grow stronger and more dexter, you'll find that you can explore earlier levels without wearing weapons. If you're lucky, you can play up to level 8 without them.You'll find it's next to impossible to get through level 12 and 13 alive without missile defense, so get some potions in stock. Race through these levels using Magic Mapping scrolls, etherealness and Missile Defense.

For more information on gameplay, monsters and magic:
LAD index
LAD monsters
LAD magic