How to catch a pokemon...
1.) Finding a pokemon
Anywhere there are pokemon available, you can catch them. Most of the time, it will be grass or water. However, in certain special areas (ie, the Rt 111 Desert in Ruby/Sapphire), you can catch pokemon without grass or water.
Anytime you move, you may encounter a wild pokemon. Not even move a step, but turning will do that (hint for the safari zone - just turn around to save step count.)
2.) When you throw a Poké Ball at a wild Pokémon, the game uses a formula based on the wild Pokémon's current health, any status effect it may have, and that Pokémon's Catch Rate, to determine your chances of catching that Pokémon. The formula is as follows:
(((( 4 x TotalHP) - (2 x CurrentHP)) x CatchRate ) / TotalHP) + Status
CurrentHP = The wild Pokémon's current HP.
TotalHP = The wild Pokémon's total HP.
CatchRate = The wild Pokémon's catch rate, listed in the psydex. This can be modified with the use of different Poké Ball types, listed below.
Status = If the wild Pokémon is Asleep or Frozen, it equals 11. If the wild Pokémon is Paralyzed, Poisoned or Burnt, it equals 6. Otherwise, it equals 1.
After all these values have been calculated, the game computes a random number from 0 to 255. If this random number is less than the number calculated above, the Pokémon is caught. If the random number is greater than the calculated one, it won't be caught.
The catch rates are found in the psydex, and can be found in the stats section. PorygonZ is an example:
The pokeballs modify the capture rate through multiplication:
Q: I heard that pressing *insert key combination* will change increase my chances. Why isn't it listed here.
A: That is by all reports through hackers and techno geeks completely false. The only answer i may offer is luck, or faith. Or, it could change that random number (again, unconfirmed).
Q: I don't have a masterball. How do I catch ______ ?
A: False Swipe it to 1 hp, put it to sleep or freeze it, and chuck Net balls (If water), or Timer Balls. Remember, after 10 turns, the ultra ball = the timer ball.
Q: I have emerald, and I want to catch Kyogre. Would the dive ball be better, the dive ball or the net ball?
A: For those not familiar with emerald changes, here's the overview: Kyogre is found in an underwater cave. However, he is on dry land. The answer is: I don't know. Yes, you must dive, but you aren't catching him under water. the true difference between the dive ball and net ball is only 0.5 . So, just to be safe, use the net ball.
Q: Can you go over some examples?
A: Give me the example, and I will gladly calculate it
Q: (by benjibob) How do I know how much hp is left on the pokemon?
A: Estimate. If its like 1 bar above fainting in the red, consider the hp as like below 10. Also, the colors indicate the amount of hp left. To find the total hp, go to th stat calculator, type in the pokemon, put in the level. Nature has no effect, and EVs = 0. So, just try to guess.
Q: I have a question, but its not on the FAQ
A: Post in this thread, and the question will be shown (with credit)