Originally Posted by Fat Jellicent
Changes from GSC to RBY
- Rather than Special Attack and Special Defense stats, Pokemon simply have a Special stat that functions as both.
- Items do not exist.
- Sleep lasts for 1 to 7 turns. Also, a Pokemon cannot attack on the turn it wakes up. A Pokemon using Rest will wake up after 2 turns rather than 3.
- The probability of critical hits is determined by Speed.
- Bug is super effective against Poison and has normal effectiveness against Ghost, Poison is super effective against Bug, Ghost is not very effective against Psychic, and Ice has normal effectiveness against Fire.
- If a Pokemon KOes an opposing Pokemon with Hyper Beam, it does not have to recharge the next turn.
- A frozen Pokemon will not randomly thaw out.
- A poisoned or burned Pokemon loses 1/16 of its health rather than 1/8.
- A Pokemon hit by a partial trapping move cannot attack for the duration of the attack.
- Steel and Dark do not exist as types.
It would be good to clarify that critical hits are based on *base* speed, and not actual speed (ie, critical hit chances aren't affected by speed boosts or drops) - that's something people get confused about a lot.
Also, in Gen I, Psychic is actually immune to Ghost, rather than not very effective as you state.
EDIT: In Gen I, when you rest off a burn or paralysis, you maintain the attack and speed drops, respectively, until you switch out. Is that true in later gens?