Amnesia Slowbro has gone down in history as one of the most famous and well-known sets in the world of competitive Pokemon. Generally known as Tobybro, Amnesia Slowbro is a moveset that combines both simplicity and efficiency. The RBY version of Amnesia is arguably the best stat-boosting move of all time, raising the Special stat by two stages. It quickly powers up Slowbro's Special moves, while covering its main defensive weakness: Electric-type attacks. Having one of the best physical defense stats in the game and learning Thunder Wave to make up for its awful Speed greatly helps make Slowbro more threatening as well. However, Slowbro is also a bit of an all-or-nothing Pokemon and requires some luck, which are the reasons why it's often an overlooked Pokemon. Without setting up, Slowbro is basically a useless Pokemon; it can't Recover to work as a wall for a long time, and offensively, it lacks Explosion or a sleep move unlike other specially-based Pokemon. On the other hand, if Slowbro sets up, it's meant never to switch back, so the user is inevitably taking some risks; Electric-type moves fail to get past a +6 Slowbro normally, but with a critical hit, a non-STAB Thunderbolt will nearly OHKO Slowbro while a STAB Thunderbolt will OHKO outright. With critical hit rates being much higher in RBY than in later generations, it's not really "bad luck" when Slowbro ultimately ends up dying to a critical hit Thunderbolt. To a lesser extent, this can also be applied to the physical side, potentially turning 4HKOs into 3HKOs, letting a physical sweeper get past Rest. However, while it's true that Slowbro depends quite a bit on luck, it also requires a good deal of skill, and Slowbro can be one of the most dangerous Pokemon in the first generation, being the best Amensia user in RBY after Mewtwo.
Everybody knows the set, but this doesn't make it less dangerous. Amnesia boosts Slowbro's decent Special, being able to reach the maximum 999 after three Amnesia boosts, letting Slowbro 2HKO Chansey with its STAB Surf at +6. When playing Slowbro, it's really useful to know some significant damage rolls or otherwise have a damage calculator handy. As said, Slowbro has a good chance of 2HKOing Chansey but must be at +6. The same can be said about Starmie, although a base 999 Special STAB Surf is a guaranteed 2HKO. On the other hand, Starmie is much more of a problem for Slowbro due to having a much higher critical hit ratio. Beating Tauros is about using Amnesia once and then 2HKOing it with Surf, although a +4 Slowbro stands a good chance of OHKOing Tauros. Snorlax, however, requires Slowbro to use Amnesia twice to get the 2HKO; a +6 Surf almost never OHKOes Snorlax. Zapdos also requires two Amnesia boosts, while Jolteon, like Tauros, is 2HKOed by a +2 Surf. Gengar will fall to two +2 Surfs half of the time, so it's generally advised to only use Amnesia once. Exeggutor and Lapras are 3HKOed by a +6 Surf; boosting either twice or three times is the way to go. All these calculations have been made considering that the opposition is at full health, so they may vary depending on the health of the opponent as well as on the situation of the battle itself.
Having said that, using Thunder Wave first is almost always a good idea. Slowbro is tied with Snorlax as the slowest Pokemon in the game, so paralyzing Snorlax is also a good idea to guarantee Slowbro is faster than it or to fish for full paralysis. Against common Slowbro switch-ins, such as Starmie, Gengar, or Electric-types, Thunder Wave will have to be used as they switch in, so that you can get a boost before they are able to attack. However, it's generally advised to switch Slowbro back after paralyzing the switch-in to get the chance to move two consecutive times the next time they switch in. This way, you can maximize your chances of KOing said check before they are able to score a deadly critical hit Thunderbolt. Even if Starmie or Chansey paralyze Slowbro back in order to outspeed again, using Thunder Wave yourself first was the best move, because the chances of beating an unparalyzed Chansey and especially Starmie are slim, as they can just keep using Recover or Softboiled until Slowbro gets fully paralyzed and they get a chance to use Thunderbolt. An unparalyzed Starmie can also attempt to PP stall Slowbro out of Surfs as well.
Rest is perfectly suited for Slowbro. During the setup, Slowbro generally takes some residual damage and gets paralyzed, but Rest can keep Slowbro healthy and free of status. After maximizing its Special, no special attack can get past Slowbro's Rest without a critical hit, and due to Slowbro's great Defense and lack of exploitable physical weaknesses, it's going to be hard to beat Slowbro from the physical side without Explosion. Tauros, for example, needs a critical hit Body Slam and Hyper Beam to 3HKO Slowbro, which is the only way it has to get past Rest; furthermore, if Tauros gets paralyzed, its chances of beating Slowbro become very small. Snorlax, meanwhile, will generally have to resort to Selfdestruct to take Slowbro down. Rhydon has the luxury of being able to 3HKO Slowbro with its powerful STAB Earthquake most of the time, but will have to switch into the predicted Rest and is OHKOed by even a +0 Surf. As said, Explosion makes a good way to eliminate Slowbro, but an Explosion might not even guarantee that a full health Slowbro goes down or gets revenge killed easily due to Slowbro's already mentioned great Defense. Exeggutor's Explosion, for instance, will only hit Slowbro for around 60%. Lowering Slowbro to around 80% or forcing it to Rest first is the safest way to ensure that one Explosion is enough to let a physical attacker, such as Tauros, Golem, Rhydon, or Persian, to revenge kill it safely.Team Options & Additional Comments >>>
Psychic is a STAB alternative to Surf, and trades 5 extra power for a 30% chance of scoring a Special fall. As far as type effectiveness is concerned, Psychic gains a neutral hit against Lapras and Cloyster and a super effective hit against Gengar and Victreebel, three of which are effective Slowbro checks, but loses the neutral hit against Alakazam as well as the ability to OHKO Golem and Rhydon at +0, needing two Amnesia boosts to OHKO them. Seismic Toss Alakazam in particular will have the opportunity to force you to Rest before Slowbro is able to get past it. Psychic's lower PP could also be a problem against users of recovery moves, especially considering that, without Surf, Alakazam will also require more time to take down. It could also be an issue if your opponent keeps using Recover or Softboiled and gets lucky with full paralysis. Having 8 less PP could also be significant in an odd Slowbro war.
Ice Beam is another attacking move Slowbro can use. Its biggest upside is hitting Grass-types and Zapdos for super effective damage, including Exeggutor and Victreebel. Ice Beam will often surprise Exeggutor, OHKOing it at +6. At the very least, it will force Exeggutor to use Explosion earlier, making it more predictable. Meanwhile, Zapdos is 2HKOed by a +2 Ice Beam and OHKOed when Slowbro is at +6. Ice Beam's freeze chance might also save you in a pinch and could make a difference against another Slowbro or Amnesia Snorlax. Ice Beam, however, should only be used over Thunder Wave, because the STAB move is necessary to 2HKO Chansey and Starmie. Withdraw has the same goal as Reflect, with the difference that it can maximize Slowbro's Defense, but requires two turns to reach Reflect's potential. Reflect will generally turn out to be more useful and safer. Withdraw's high PP will let Slowbro outstall other Slowbro, however. Counter can surprise common Slowbro switch-ins like Starmie if you switch into a Body Slam from a physical attacker and scare it out, or if you predict a Hyper Beam. Counter has hardly any other uses other than these though, because Slowbro generally only takes physical attacks when it's asleep, excluding Explosion. Disable is a funny option that can prevent some Pokemon from Thunderbolting Slowbro for some time, but it's very unreliable and shouldn't really be used.
Checks and Counters
Starmie or Chansey packing Light Screen will completely counter Slowbro unless they get really unlucky with full paralysis. Light Screen is never seen on them, however, as it has no use outside of walling Slowbro. Victreebel and Venusaur are known for having a guaranteed critical hit in their STAB signature move, Razor Leaf. They won't like switching into a Thunder Wave, and could be surprised and OHKOed by a boosted STAB Psychic, but, otherwise, either of the Grass-types can KO Slowbro when it is below 70% or 2HKO it while it is Resting.
Apart from these, Slowbro has no safe counters. Thunderbolt users are possible choices; the higher their critical hit ratio and amount of turns they can resist Slowbro's Surf, the better counters they are. Starmie is a good choice, having a very high Speed and thus a high critical hit ratio, while also resisting all of Slowbro's moves. It's not a surefire counter though, and in case Starmie prevails, it won't like having to eat a Thunder Wave. Gengar makes a good choice too, having a high critical hit ratio and being able to Explode for around 50% damage when it's about to die. However, it doesn't resist Surf and is weak to Psychic. Zapdos and Jolteon have the luxury of getting STAB in their Electric-type attacks; even when Slowbro is at +6, their Thunderbolts will still do significant damage. They also have a high critical hit ratio, but like Gengar, they don't resist Surf, and, unlike Gengar, can't Explode. Regarding Explosion, it makes a very viable choice for taking Slowbro down when you have no other option. It won't OHKO a healthy Slowbro, but could put it in the KO range of Tauros's Hyper Beam or Rhydon or Golem's Earthquake. Pokemon with Explosion include Exeggutor, Snorlax, Golem, Cloyster, and Gengar, although Gengar's Explosion is weaker. A Resting Slowbro that gets Exploded on is pretty much a dead Slowbro.
Amnesia Snorlax will often defeat Slowbro, as its Body Slam is an almost guaranteed 4HKO while Slowbro's Surf only manages a 5HKO when both are at +6. Due to the Speed tie, a 4HKO could turn into a 3HKO, depending on who goes first the turn Slowbro uses Rest. If Snorlax is packing Thunderbolt instead, it will fare even better, 3HKOing Slowbro after both have set up. As far as the physical side goes, Rhydon makes a surprisingly viable option, although risky as well; it has to switch in when Slowbro uses Rest, and then try to 3HKO it with its STAB Earthquake, which will happen around 75-80% of the time. Tauros needs a critical hit Body Slam to get the chance to 3HKO it after finishing it off with a Hyper Beam. If Tauros gets paralyzed, though, you can pretty much forget about beating Slowbro. Snorlax's critical hit ratio is much smaller than Tauros's, but its Body Slam is almost a guaranteed 4HKO, and has an easier chance if Body Slam paralyzes Slowbro. For instance, if Snorlax moves first while Slowbro tries to use Rest, but moved last on the previous turn that Slowbro Rested, Snorlax beats Snowbro with only Body Slam. Both Tauros and physical Snorlax should really be careful when trying to counter Slowbro and should generally only be sent in when Slowbro is sleeping because they will otherwise die to previously-boosted Surfs more often than not.
If Slowbro's set contains Reflect, though, trying to counter it with physical attacks becomes impractical unless you are willing to sacrifice at least two Exploders. In this case, however, any unparalyzed Thunderbolt user becomes a much more effective check, including the slow ones, such as Chansey and Lapras, which, despite their low critical hit rate, will get more chances to fish for it, as it's much more likely that Slowbro is forced to Rest more often. Chansey and especially Starmie will get the chance to keep using their recovery move until Slowbro gets fully paralyzed, which is when they get the chance to use Thunderbolt. Starmie is much better at doing this because Recover outlasts Surf in terms of PP.
It's worth noting that Slowbro, as a Rest user, is one of those Pokemon that should be attacked whenever given the chance, because when it's Resting, you can apply a much higher and more effective variety of tactics to try to take it down. Exeggutor's Mega Drain and Alakazam and Jynx's Seismic Toss, for instance, may not do enough to kill Slowbro, but will cause some decent damage on it before being forced to switch out, which will force it to Rest earlier than desired.