First off, Rampados is not available in Gen 8 (SwSh) at the time of writing. You can use Rampardos effectively as a wallbreaker in older gen's lower tiers, though (notably DPPt and BW. After those two gens it's competition gets better and better and Rampardos can no longer keep up. Rampardos was one of the first untiered Pokemon in Gen 5). Rampardos' highest tier is Gen 4 UU. Not bad.
Luckily for us, False Swipe Gaming just made a video on Rampardos in competitive this year.
Rampardos in general isn't a terrible Pokemon. It's a slow glass cannon, with access to 165 base attack and Sheer Force for even more power. Rampardos actually doesn't have a bad movepool. It's special movepool is suprisingly great with options like Thunderbolt, Surf, Ice Beam, and Flamethrower. As Smogon says, Sheer Force makes it's special options passable. This was actually a strategy in BW RU.
While Rampardos would normally be thought of as a one-dimensional wallbreaker, pummeling through the tier with its massive Attack, it also has the ability to go mixed due to access to Sheer Force and an expansive special movepool. The purpose of this set is to lure in Rampardos's checks and counters and destroy them with the appropriate coverage move.
(This is the set they were using)
Rampardos @ Life Orb
Ability: Sheer Force
EVs: 16 Atk / 252 SpA / 240 Spe
Rash Nature
- Head Smash / Rock Slide
- Thunderbolt
- Focus Blast
- Ice Beam
Rampardos was generally used as a Choice Band or Scarfer though. This is Rampardos' Gen 4 analysis:
Rampardos @ Choice Scarf
Ability: Sheer Force
EVs: 4 HP / 252 Atk / 252 Spe
Adamant / Jolly Nature
- Stone Edge
- Zen Headbutt
- Fire Punch
- Earthquake
Rampardos is pretty much the definition of the term 'glass cannon'. The good news? He possesses the highest base Attack stat found outside of Ubers, powerful STAB Rock-type attacks, and an awesome movepool with access to useful boosting options. On the other hand, he also has a low Speed stat and shoddy defenses with weaknesses to several common attacking types, making him extremely vulnerable to four of the most common priority moves in UU (Aqua Jet, Bullet Punch, Mach Punch, and Vacuum Wave). It goes without saying, then, that the metagame has not been very kind to Rampardos at all, and he is often shunned in favor of his bulkier competitors, who are not so easily revenge killed. Still, if you're looking for power, and lots of it, then maybe Rampardos is the Pokemon for you.
With a beastly Attack stat, and below average Speed, it would seem that Rampardos was born to use a Choice Scarf. Thanks to his unholy combination of Speed and power, he's more than capable of revenge killing early- to mid-game, and sweeping through a weakened team late-game. Stone Edge is a powerful STAB move coming off Rampardos's base 165 Attack, and Earthquake is used with it to form the excellent "EdgeQuake" combo. Thanks to Mold Breaker, Rampardos is able to use Earthquake to hit common Levitators such as Rotom and Weezing super effectively, which is a massive plus in anyone's book. Fire Punch is for Torterra, which walls the rest of the set, while also being a more reliable move to use against defensive Grass-types. Finally, Zen Headbutt is in the last slot as it 2HKOes Hariyama and Hitmontop (without Intimidate).
In Gen 6 PU though, it was a solid wallbreaker.
Rampardos @ Life Orb
Ability: Sheer Force
EVs: 252 Atk / 4 SpA / 252 Spe
Naive / Naughty Nature
- Superpower
- Zen Headbutt
- Rock Slide
- Fire Blast / Ice Beam
Rampardos is one of the strongest wallbreakers in the tier because of its base 165 Attack stat and Sheer Force, though it can also make good use of Mold Breaker to become an effective suicide lead. Rampardos's movepool allows it to hit the majority of the PU tier for super effective damage, meaning almost nothing can switch in safely. However, its terrible defensive typing coupled with its low base Speed and bulk makes it lackluster against offensive teams and easy to revenge kill. Rampardos also faces some competition as a suicide lead from Monferno and Custap Berry Golem, which can perform a very similar role. Rampardos is, however, still a usable lead, because it is able to defeat opposing Golem and Crustle easily, has terrifying power, and can stop entry hazard removal with Head Smash.
Beyond the mentioned tiers, Rampardos is niche and outclassed.
TL;DR
Rampardos is very frail and slow, which has led to it not being great on the competitive side. It had a notable niche in some lower tiers and was decent in Gen 4 UU, but other than that it's usually outclassed by other faster (although not necessarily stronger) glass cannons. I, personally, would not use it. If you would like to use Rampardos on a Gen 7 Trick Room team though, I made a set.
Rampardos @ Choice Band
Ability: Sheer Force
EVs: 252 HP / 252 Atk / 4 SpD
IVs: 0 Spe
Brave Nature
- Head Smash / Rock Slide
- Pursuit
- Zen Headbutt
- Thunder Punch
*All the quotes are from Smogon's Rampardos page.
