Normal

Poison Attacks

Psychic

Poison attacks are most effective against Grass and Bug Pokémon. (Death to Parasect!) However, some Pokémon most commonly thought of as Bug or Grass Pokémon (eg, Beedrill, Venomoth, Bulbasaur, and Vileplume), are actually half-Poison, thus making the selection of vulnerable victims fairly slim. On top of that, Poison (and half-Poison) Pokémon not only take a reduced amount of initial Poison damage, they cannot be Poisoned.

Furthermore, Exeggutor, another popular Grass Pokémon is half-Psychic, making him quite dangerous to your Arbok.

Poison attacks are weakest against Ghost, Poison, Ground and Rock Pokémon. Since all Ghosts are half-Poison and several Ground Pokémon are half-Rock or half-Poison, your Weezing is going to be in a lot of trouble against many opponents, including Gengar, Rhydon, and Nidoking.

Considering the above, as well as the relatively weak power of Poison attacks (there is no Poison equivalent to Fire Blast or Thunder), if Poison Pokémon trainers do not have a sentimental attachment to their Pokémon, they are likely to be very disappointed in the performance of their good friend Koffing.

The main benefit of poisoning a victim is the psychological effect on the trainer, as a poisoned Pokémon only loses 1/16th of its maximum HP per turn (unless they have been Toxicked, which is a bit nastier), even if they are weak to Poison attacks (1). There are no other ill effects.

Note that Pokémon affected by another major Status change (eg, paralyzed or sleeping Pokémon) cannot be poisoned. This does not include minor status changes like confusion. Take that into consideration before you teach your Muk how to Body Slam.

The converse of this has led some unscrupulous trainers to begin matches with all their Pokémon pre-poisoned, to prevent paralysis, freezing, and the like. (That gives you an idea of just how ineffective 1/16th maximum HP per turn is.) While it can be the deciding factor in a battle where the enemy is hiding behind multiple layers of defenses, the PSN status really doesn't make up for the lack of a good solid Poison attack.

When you add it all up (very few vulnerable opponents, a good number of extremely resistant opponents, low power, lame side-effect, and Poison Pokémon's vulnerability to the prevalent Mewtwo)...boy, did Poison Pokémon ever get screwed! Such a shame, since the type had the potential to be so cool.

Unlike all other Poison attacks, Acid cannot actually poison a victim. It can lower a victim's Defense...but it's just so friggin weak (and the side effect so unreliable) that something like Body Slam, even without the type-matching bonus, is a better choice. The sad thing is that Acid isn't anywhere near the weakest Poison attack! It certainly sounds cool, though.

Poison Gas and Poisonpowder do no initial damage whatsover. But if they do hit, they will always poison the victim. However, as has been mentioned above, poisoning a victim is not all that great.

To make matters worse, Poison Gas is ridiculously inaccurate. Poisonpowder isn't exactly a sure thing either. Both are a big risk for very little payoff.

Toxic also does no initial damage, and it's mercifully more accurate than Poison Gas and Poisonpowder. It's also more effective. Each turn a victim has been Toxicked, the recurrent damage increases. (For more information, see the entry on Toxic.)

Toxic is widely regarded as a good move, but it's highly overrated in any situation other than forcing a powered-up victim to switch out, or in other very specific cases (eg, in combination with Leech Seed, or against the last Pokémon standing).

It is, however, certainly one of only two non-worthless Poison attacks, and, to further illustrate how badly Poison Pokémon got the bone, nearly every Pokémon in the game can learn it and use it just as effectively as a Poison Pokémon.

Note that even though the mounting effects of Toxic are intimidating, it's only roughly twice as effective as a standard poisoning. That is, while regularly poisoned Pokémon can survive a maximum of 16 turns without healing, a Toxicked Pokémon can survive seven turns. However, it is more effective against a Recovering Pokémon than a standard poisoning, because eventually it will cause more damage than can be Recovered in a single turn, while a Recovering Pokémon can live forever (or at least until it runs out of PP) with a standard poisoning.

The biggest shortcoming of Toxic is that if the Toxicked victim is switched away, the Toxic poisoning will revert to the standard PSN status. That just about sucks all the intimidation right out of the attack.

Also, since Toxic takes a while to work up a good head of steam, it takes a number of turns to be as productive as simply firing away with a nice Sludge attack.

But this isn't a fair comparison, since Toxic has to be thought of as a specialty attack, along the lines of Thunder Wave or Confuse Ray. It is not a good attack to use as your primary means of dishing out damage, in the general case, but it can prove decisive if conditions are favorable and it's used properly.

It should be noted that the oft suggested Toxic/Wrap combo is not all it's cracked up to be. The Wrapped Pokémon can be switched out (perhaps to Pokémon more resistant to the Wrap), forcing the attacker to attempt another successful hit and reverting the Toxic to standard PSN. It'll work well if this is the opponent's last Pokémon, but if that's the case, it isn't going anywhere anyway. But at least it would prevent the opponent from attacking and/or healing, and allow you to actually do some decent damage while Wrapping (or Clamping or Fire Spinning).

Poison Sting is so amazingly laughably weak that it's not worth having at all. And even after hitting with it three times, there's no guarantee that the victim will be poisoned. Next.

Just when you thought Poison Sting was the krappiest attack you've ever seen, along comes Smog.

Sludge is clearly the best Poison attack, but it's still not all that great. As mediocre as it is, however, it kicks Smog's poofy ass all to Hell and back. Both have a reasonably good chance of poisoning the victim, but as has been repeatedly harped upon, this is no big deal. Also, in the case of Smog, remember that the chance to poison is only factored in after it hits. When you take its poor Accuracy into account, its chance to poison is actually only about 25% (less than Body Slam's chance to paralyze).

Sludge is just about as accurate as an attack can get and also does the most initial damage of any Poison attack. Even so, it does much less initial damage than a solid elemental attack like Surf or Thunderbolt. It would seem that the potential for poisoning a victim is the game's attempt to make up for this weakness, but in most cases, battles don't last long enough for this poisoning to close the gap.

None.

Recurrent poison damage is based solely on a percentage of the victim's maximum hit points. It is unrelated to victim and attacker stats, whether inherent or modified in battle, and has nothing to do with either Pokémon's type or Level. It is interesting to note that, because of the way the damage is calculated, the actual amount of damage inflicted by a poisoning increases as the victim gains Levels.

Each time the poisoned Pokémon attacks, it will lose 1/16th of its maximum HP immediately following the attack, unless the opponent faints as a result of that attack.

The following brave Pokémon subjected themselves to poisoning in the name of Science:

Pokémon	Level	Max HP	PSN Dmg
Magikarp	95	203	12
Dodrio	100	291	18
Psyduck	100	299	18
Butterfree	98	310	19
Wigglytuff	100	453	28

(Note that Butterfree's vulnerability to Poison had no impact on the damage.)

These were the pioneers in our Poison research, which led us to believe that poison's Magic Number was 6.3%, which was pretty darn close. It was later hypothesized that the damage was 1/16th of max HP, or 6.25%. All remainders are dropped, as the Game Boy does not like to round.

To test the theory that the Magic Number is actually 6.25%, the following Pokémon, of varying Levels, braved the rigors of Poisonpowder:

Pokémon	Level	Max HP	PSN Dmg
Rhyhorn	25	79	4
Golem	25	80	5
Lickitung	23	81	5

In this case, we have further evidence that Poison is unrelated to Level. Rhyhorn and Golem's resistance to Poison also had no impact on the damage.

Unfortunately,

79 x .0625 = 4.9375 79 x .063  = 4.977

and

80 x .0625 = 5 80 x .063  = 5.04

So, working under the assumption that remainders are always dropped, this doesn't distinguish between 6.25% and 6.3%. We still need further clarification. Also, to eliminate all other factors, the same Pokémon was used in the final trial. An Alakazam was fed HP UPs to bump up his HP (and nothing else):

Pokémon	Level	Max HP	PSN Dmg
Alakazam	47	126	7
Alakazam	47	127	7
Alakazam	47	128	8
Alakazam	47	129	8

This time:

127 x .0625 = 7.9375 127 x .063  = 8.001

and

128 x .0625 = 8 128 x .063  = 8.064

So it's obvious now that .0625 (or something so close that even we don't care what it is!) is the dividing line. (Actually, the CPU is actually probably doing a "bit-shift" operation, but since that's identical to multiplying by 1/16 and dropping the remainder...who gives a damn?)