This little tutor was written by me, David Biggs in just a few hours 
and I reackon it's heaps better that other tutors around cos it's real
simple and graphical. Just go through step by step and soon enough
you'll be creating your own mega levels.

Contact me at for coments or whatever.

++++++Making a small level with DEU 5.21+++++++++++

    This is a guide to making a simple level With the Doom Editor 
Utility or DEU. It will show you how to make 2 rooms with a door and 
a table in one room.
    Okay, first of all, you can't have a single-sector wad (I don't 
think you can, but just in case...).  So make lets make the first 
sector. Go to the "Misc" menu select "Make recangle". When the 
dimension box comes up make the room 256 * 256. This a reasonable 
sized room considering the average corridor is about 128 wide. The 
purple cirular display the appears shows dimension with each circle 
being 128, 256 and 512 units wide, this helps to get the right scale 
of your level. To change use Tab to change the second number.
    Your level should look like this
                    ║         |        ║
                    ║                  ║
                    ║                  ║
                    ║--              --║
                    ║                  ║
                    ║                  ║
                    ║                  ║
                    ║         |        v   <--- arrow head
    If is is really small use "+" and "-" to zoom.
    Now if you press "S" for sector mode the box should turn yellow, 
this means the sector is defined. If it is undefined then it will be 
in thin Red lines.

    Now lets add another small sector to the level. Add some vertices 
to the level by pressing "v" for vertice mode. Add the vertices like 
this.......x represants a vertice.

                    ╔══════════════════x  x
                    ║                  ║
                    ║                  ║
                    ║                  ║
                    ║                  x  x
                    ║                  ║
                    ║                  ║
                    ║                  ║
                    ║                  ║
    Now select each vertice with the left mouse button in this order.
                    ╔══════════════════x1 x2
                    ║                  ║
                    ║                  ║
                    ║                  ║
                    ║                  x4 x3
                    ║                  ║
                    ║                  ║
                    ║                  ║
                    ║                  ║

    Then press insert and lines will be placed between the vertices. 
Now you make sure those things hanging on the right side of the 
line point inwards
    The lines should be like this    
                                      ║   |  |
                                      ║     -|
                                      ║   |  v
    They must point inwards into the sector because when you make 
lines into a sector, the editor will add a texture on that right side 
of the line with the small line. This side is called the "first side 
     Now go to line mode and by pressing "L" and select all the 4 
lines of the new box with the mouse then press insert. This makes 
the lines into a new sector.

   It should look like this
            ║          ║ 1 ║
            ║          ║   ║
            ║          ╠═══╝
            ║     0    ║
            ║          ║

    The level is almost ready to try. Add a player one postion by 
pressing "T" for Thing mode. Press insert for the start position 
somewhere in the big room. Then click on the item and press Enter to 
modify the thing. Change it to a player 1 start position.

    Now you should be able to try the thing out.  But first press F10 
and do all the checks and it should be fine.

    Now save you level and exit. There will be some messages 
concerning Multiplayer starts and deathmatch level start but we don't 
need them yet. Say yes when it asks to rebuild nodes etc so you can 
try you level.

    Then quit back to dos and load you level by typing 
    Doom -file whatever.wad
    It should work fine.

Now lets add another room and a door

Go to vertice mode and put in 3 more vertices like this

            ╔══════════╦═══╗        x  
            ║          ║   ║
            ║          ║   ║
            ║          ╠═══╝
            ║          ║
            ║          ║
            ╚══════════╝   x        x

        And select the vertices in this order and then press insert to 
make the lines.

            ╔══════════╦═══x1       x2  
            ║          ║   ║
            ║          ║   ║
            ║          ╠═══x5
            ║          ║
            ║          ║
            ╚══════════╝   x4       x3

    Then it should look like this.

            ║          ║   ║          │
            ║          ║   ║          │
            ║          ╠═══╣          │
            ║          ║   │          │
            ║          ║   │          │
            ╚══════════╝   └──────────┘

    Go to line mode and select all the lines of the new box including the line attached to sector #1 and press insert to make it a sector and you will have 3 sectors like this.

            ║          ║ 1 ║          ║
            ║          ║   ║          ║
            ║    0     ╠═══╣    2     ║
            ║          ║   ║          ║
            ║          ║   ║          ║
            ╚══════════╝   ╚══════════╝
    Do the checks again with f10, save your level again and check it 
out. It sould all be working just fine.    

+++++++++++Adding a door+++++++++++++

Now let's add a door, press "s" for sector mode and select the 
centre sector, Number 1

GO to the menus and select "create door from sector" and wallah! 
have a door and 2 rooms......It's that easy! But When you make your 
own, make sure you have rooms on each side of the door firsat 
otherwise it will have errors.

Save again and check the door.......

************ A table in a room ++++++++++++++++++++++++ 

Firslty insert a rectanlge in the second room. Do this by Zooming in 
and centring the second room on the screen. Then selecy "make 
rectangle" and lets make it about 64*56 just for fun.

it should be like this

            ║          ║   ║          ║
            ║          ║   ║   ╔══╗   ║
            ║          ╠═══╣   ║  ║   ║
            ║          ║   ║   ╚══╝   ║
            ║          ║   ║          ║
            ╚══════════╝   ╚══════════╝

    then select each line of the new box and press insert again to 
make it a sector. This is because so far it is only attached to the 
outer sector. You need to define the inside as well.

now press s for sector mode and select the sector you just made.

press enter to modify the sector and change the floor height to be 
equal to the height you want. The ceiling hieght is probably 128 so 
make the floor around 35.

Now press "L" for line mode. Now look at a line of this new table 
sector. You will notice that they have written in red "Lower texture". 
in the "first side def" section.
    In red means that you need to assign a texture here but haven't, 
so select all the lines of the pillar sector and press "Enter" to 
modify them. Go to "Edit first side def" and change the lower 
texture to what ever you want.

And you're all set expept we need an enemy don't we. How can we play 
doom without killing something.

Press "T" for thing mode. press insert where you want to add and 
enemy soldier then enter to modify the "thing". Change it to a 
soldier or demon or what ever you want by going to "enemy" but 
remenber unless you cheat you'll only have a pistol.
    Don't place it 1/2 way into a wall though as it will get stuck in 
the wall.

Now you should be able to try the level out.  But first press 
F10 and do all the checks and it should be fine.

Now try out you level and It should be fine.
        You've created your first level!

++++++++++Side defs++++++++++=
Now I'll explain Side defs.

You would have noticed all the lines look like this

The side with the bit sticking out is the "1st side def" and the 
other is the "2nd side def". Like this

                   2nd side def
                        │ 1st side def
The bit is always on the same side of the line. If you are only 
ever going to see one side of a normal wall it must be the 1st side. 
That's why you select the vertices in that order. So all first side 
defs will be pointing in.


You will notice that each side def has "Normal", "Upper" and "lower" 
textures. Now a "normal" texture is just for and wall etc with no 
strange bits...just yor average wall.
    An "upper" texture is used for doors and places where the ceiling 
height changes between sectors and also for doors.
    A "lower" texture is for places where the floor changes in height 
between sectors such as stairs. 

    For example......I you have a room with floor height 0 and 
ceiling 128 and another beside it with floor 20 and ceiling 100 then 
you have a difference in floor and ceiling.

So it would look like this if you looked from one tall sector into 
the smaller one
                │               │
                │               │
                │               │
                │               │
                │               │
                │               │

Now the textures are like this

                │upper texture  │
                │               │
                │normal texture │
                │               │
                │ lower texture │

But You would have no normal texture as you want to see through this 
pat of the wall.

    Now that about covers all the easy stuff there is to explain. Once 
you've figured out this much and can confidently apply it to your own 
level you should have enough skill to do any thing you want. But 
remember to do the check with F10 and if you have probs..Fiddle a 
bit. You'll learn a lot just by fiddling around with different things 
and experimenting. But if all else fails, Bang you head against the 
monitor then mail to or get on #doom IRC for freindly 
(most of the time) advice. See me there under the nick of "HotFat". 
I'll do my best to help you out. Or email me at the address above.