Rules are simple!
Choose a Move and attack!
Moves do certain about of damage. The Attacks have PP and when they run out u have to wait for them to recharge. Also effectiveness counts! So if a move does 25 damage and the attack is 2x effective it does 50 damage. Also if the number isn't a whole number like 12.5 then you just drop the decimal so it do 12 damage so NO rounding up.
(+)There be normal power bonus of 5 additional damage if weather is the same as the attack like flamethrower on a sunny day.
(-)But it also works the other way like flamethrower on a rainy day it loses 5 damage.
Sunny Day /Fire and grass attack (+)/ water and Electric attacks (-)
Rainy Day / Water and grass and Electric (+)/ Fire (-)
Sandstorm / Ground and rock (+)/ Water, electic, fire, and grass (-)
Hail/ Ice (+)/ No (-)
Weather effects only the next move.
Also when these weather moves are used it does 5 damage to certain types. Sunny, Rainy, and Hail does damage to those that are weak agaist those moves and sandstorm hits all besides rock and ground types. They do 10 damage all the time NO added effect.
Here are the moves with PP.
Any attack that does 25 damage (PP 5/5)
Blizzard Fire Blast; Thunder; Horn Drill; Psychic; Hydro Pump; Freezy Plant; Crunch; Cross Chomp Earth quake
Any attack that does 20 damage (PP10/10)
Milk Drink(recovery 2 pokemon ); Giga drain ( does 20 damage to one poke and one poke recovers 10 ) Thunderbolt, Ice beam,
Any attack that does 15 (PP15/15)
bite; psybeam low kick Rock throw
Any attack that does 10 damage (PP 20/20)
Tackle; Absorb(damage one poke recover another by 5); Slam; Quick Attack; confusion
Any attack that does 5 damage (PP20/20)
Sunny Day; Hail ; Rainy Day ; Heal Bell (next recovery attack is increased by 10); Sandstorm
If any question post them.