The differences between gen 1 and now

Well if your playing Gen 1 you should know

Types:

• Ice Is not resisted by fire or water types, meaning Charizard is weak agnist Ice.
• Psychic is Super effective against Ghost
• Poison is super effective against bug
• Ghost cant harm Psychic

Certain Moves:

• Karate chop is Normal type
• Bite is normal type due to the non-existence of dark types.
• Gust is normal type

Certain Mechanics:

• One and perhaps the most important, Pokémon will never thaw out by them selves unless they are hit by a fire-type attack, or are hit by the move Haze.
• NPC's will always go for a super-effective move, even if its spamming agility on your poison type.
• Wrap Stops the Opponents attacks and deals 5% each turn, being the most Over-powered move if you outspeed
• Critical Hits are based on speed, meaning persian with slash has a nice and 25% crit chance.
• You can miss a Pokéball throw
• If you crit using a multi-hit move such as Fury swipes on the first attack, all attack following it will be a critical hit
• OHKO moves dont land if your slower than the opponent, but if you put aan X accuracy and your faster, they always will.
• If you use Wrap or such moves ona Pokémon that switches in newely and wrap has 0 PP left(you used it on the oter Pokémon and he switched while trapped) it will reset to 63.
• If a Pokémon is sleeping and wakes up, it will not attack, instead it will just wake up and wait to be put to sleep again, and will atttack the next turn.
• theres a 1% chance 100% accuracy moves can miss
• Counter only works againstt Fighting or normal type attacks
• If you Kill a Pokémon when using Hyperbeam, you dont have to recharge, this also works if it breaks a sub.

There are many more but i cant think of more of the top of my head rightnow, but feel free to bother me if you want to know more, or just look it up