At some point in your programming career you're gonna be showing a piece of code to someone for whatever the reason and you're gonna get this response: "What in the name of the Harlem Globetrotters does it
do?" (or at least something along those lines) It will happen to us all, it's already happened to me twice, and it
will happen again. Why? Because sometimes code is hard to understand, particularly un-tabbed code. What's un-tabbed code you say? Take a gander:
var1 = RANDOM 5
var2 = RANDOM 5
IF var1 = var2 THEN
var3 = RANDOM 5
IF var3 = var1 THEN
CLEAR TEXT
PRINT Awesome!
END IF
END IF
Here's a tabbed version of the same code:
var1 = RANDOM 5
var2 = RANDOM 5
IF var1 = var2 THEN
 var3 = RANDOM 5
 IF var3 = var1 THEN
  CLEAR TEXT
PRINT Awesome!
 END IF
END IF
Notice how the latter is easier on the eyes? That's because the "conditions" have been tabbed, making it easier to deduce which lines of code are under conditions. But what's that you say; what's a condition? A condition is simply a line of code that allows the execution of
more lines of code providing a specific requirement is met. The most basic condition is IF THEN, but other commonly used conditions are ON KEYDOWN and ON TIMER.
Take a look at the following example. The red text highlights the code that's under the IF THEN condition:
playerHP = 20
enemyHP = 25
IF enemyHP > playerHP THEN
 CLEAR TEXT
 PRINT The enemy has more HP than you.
END IF
Everything between the lines IF THEN and END IF have two spaces typed before the command. Here's another example with "Nested Conditions", which means you have a condition block
within a condition block:
X = RANDOM 10
IF X = 10 THEN
 X = RANDOM 20
 IF X = 20 THEN
  BEEP
  ALERT By golly them's high odds!
 END IF
END IF
This time I've used green text to represent the nested condition. As you can see it's nice, clean, easily readable and 99% fat free.
So, tab your code chaps. It makes it easier to read and by extention easier to locate bugs and glitches.