Random Number Generator
Parents: When you find the spread you want, you will need some parents to pass down IV's. If you are new to this, you likely don't have any good parents or dittos, so you will need catch some. Pokemon with the ability Synchronize and the nature you want your Pokemon to have are very beneficial for catching Ditto. Abra, Ralts, and Natu are all found in Emerald, however they are all pretty rare. If you have Fire Red/Leaf Green and have the Ruby and Sapphire Stones, you can use my favorite trick. Buy some game corner coins and save in front of the prize desk with only 1 party Pokemon. Buy 5 Abras and check their nature and whether they have synchronize. If none of them have your desired nature and synchronize reset the game and try again. Once you find one you want, trade it over to emerald. In emerald, buy as many repeat balls as you can. Also fish up a Magikarp. Fly to the Digger's house and go into the back of his house into the tunnels. Have Abra first in your party, and Magikarp and a high level Pokemon in the back. When you find a Whismur or a Loudred, switch to the high level Pokemon and run. When you find a Ditto, switch to Magikarp and throw a repeat ball for a 100% catch success rate. When you have a bunch of Dittos, check their IV's using Metalkid, The IV Man, or by glancing at the stats if you have them memorized.
Now it's time to start. Load up the RNG Reporter and in the "Method" box, select "Breeding (Emerald Splits)". On the right side of the screen you will notice rows for "HP", "Atk", "Def", "SpA", "SpD", and "Spe". If you want your baby to have a 31 or a 30 in that stat, select those two options. If you don't care what your baby has, leave it how it is or if it's already filled in, select "Clear". If you want your baby to have an IV that's not 31 or 30, type it in the box, and in the drop down menu select the "==". If you want it to have an IV greater than or less than the number you typed in, select the ">=" and the "<=" respectively. Once you type in the stats you want your baby to have, select "Generate" on the far left of the screen.
If you are really new to this and aren't willing to spend a lot of time trying to get the IV spread you want, avoid selecting a split spread, labeled with an "S" after their Frame Number which is found in the "Frame" column. However, they aren't much harder than normal spreads, but they require more precision, accuracy, and generally more attempts. When you find a spread that doesn't seem to take a lot of time, check which stats have which letter in them. Now, you need to breed your Dittos and any other Parents you may have until you have one parent that is able to pass on the stats lettered "A" or "B", and one other parent that is able to pass on the stats labeled "A" or "B". This means that whatever IV's your parents have for the stats labeled "A" or "B" the baby will also have. Remember to also have an everstone attached to either the Ditto with the nature you want the baby to have if it's breeding with a male, or the female with the nature you want the baby to have if it's breeding with anything. The parent that you plan to have pass down the IV's for the stat(s) with the "A", place in the daycare first. The parent that you plan to have pass down the IV's for the stat(s) with the "B", place in the daycare last. When the old man has an egg, save the game in front of him, and hatch the egg. If the egg has the nature, gender, and ability you want, then shut the game off without saving. When you turn it on, reset the game(start+select+a+b) and press the "Start" button on the stopwatch at the same time. Start the game and talk to the daycare man until he gets to the part that says, "Take Good Care of it!" When the stopwatch gets to the time required for your spread, which is listed next to the frame in the "Time" column, press the "a" button to accept your egg.
Hatch the egg and determine the IV's. If they are the IV's you want, save the game. If not, check the IV's, and scroll up and down from the spread you're aiming for in the RNG reporter to find the IV spread your baby had. Even if you hit your spread at the exact time required, you may still be off, so adjust your timing and shoot for a little higher/less than the required spread. Once you determine how off you were, shut off the game without saving and try again.
If you don't have a stopwatch, this online one is very easy to use and works really well.
Click here for part one of the Emerald RNG Guide
Click here for part three of the Emerald RNG Guide