I'm laddering frequently on the Showdown OU ladder, hovering around top 500 when I do invest the time, so I hope I can give some helpful input:
First of all, your statement
I dont want any legendaries or ultra beast in the team, since they are just unfair regardless.
contradicts your intent, namely building a competitive team. If you want to build something that competes amongst the best in the tier, that sometimes implies including some legendary/UB or the other. There is
no such thing as unfair Pokémon, there are inferior and superior strategies. The tiers decide what's "fair" and what's not.
Next -
what are you targeting exactly? I don't know how much you know about the formats but you basically have VGC and the Smogon tiers. The prior is basically the rules applied to Ranked Doubles (and Battle Spot Singles, kind of), while Smogon tiers are what is played on Pokémon Showdown (an amazing site to learn competitive battling, in case you didn't know that yet. Just throw some Mons together, build a team in a matter of minutes and test it on the ladder with super low que times against all players of all levels.)
I will just give you some insights on the terminology, how to get started, where to find valuable information, how to learn, ... - it's up to you how you want to apply it and how much exactly you want to commit to a more competitive style of Pokémon.
So let's say you were to decide on building an
OU Singles Team, OU as in OverUsed which is the most common tier on Smogon. Both Singles as well as Doubles have certain "unwritten" rules for them. In this example I'll focus on Singles for now.
There are certain
types of teams:
- Hyper Offense (pretty much no defensive Mons, All-In strategy, reliant on predictions, heavily punished by mistakes, heavily rewarded by proper aggressive play, ends games fast)
- Mixed (built to have an answer to anything, does not excel in any particular strategy, gives you alot of options, may have problems against certain archetypes as you simply cannot cover every weakness, gives you some breathing room even when making mistakes)
- Stall (very slow-paced, tilt inducing types of teams with at most one offensive Pokémon in them, tons of recover moves, status afflictions, entry hazards, very hard to break through for your opponent, makes many people ragequit, a game can take ages)
- Semi-Offense/VoltTurn Momentum (mostly offensive Pokémon but has 1 or 2 walls to fall back on, has many means of seizing switch initiative, not as committal as Hyper Offense, a single mistake won't cost you the game right away)
- ...
→ You can be more specific and come up with more archetypes as you please, but these have established as the main ones people refer to
How these teams are played, common Pokémons in them, how to face of against them, which one counters which etc. are things you learn down the road. For now it's just important to know they exist, and that your team will be one of these archetypes.
There's
alot of terminology when it comes to competitive Pokémon, so let's just get some out of the way:
- Check: Something you can bring in on Mon X safely, knowing it will take any hit etc.
- Counter: More severe form of a Check, as it not only checks but also directly counters, i.e. winning 1on1.
- Trapper: a Mon meant to be brought in against certain target Mons to then kill them - e.g. through the means of Arena Trap, Magma Storm, Infestation, Magnet Pull, Pursuit etc. - once the Trapper is brought in vs. the "trapped Mon", it is dead or about to be.
- Wall: a Wall is closely connected to being a Check. To be able to wall Mon X means there is no possible way for it to force you to switch out, as none of its moves will ever be able to threaten you. E.g. the Wall takes less than 50% by any moves and has Roost. Or the opposing Mon gets walled because it lacks set-up moves and will never outdamage your recover moves. Walling could also be referred to e.g. Gengar vs. Chansey, where it is both immune to Toxic and Seismic Toss, thus being completely unaffected by most of Chansey's sets. Though this could also be referred to as a Stall Breaker or Counter.
- Stall Breaker: a Mon meant to break through afore mentioned archetype, e.g. by carrying the move Taunt which stops Pokémon like Sableye, Chansey, Toxapex, Gastrodon, M-Venusaur, ... from using Recover moves, Leech Seed, Toxic, Will-O-Wisp etc. Often times they also bring set-up moves or Def/SpDef drop moves like Shadow Ball, to be able to - after some defense drops - tear through those stall Pokémon.
- Wall Breaker: very similar to a Stall Breaker, though specifically targetting Walls. They are the primary reason your Setup Sweeper cannot yet win you the game, as there are certains Pokémon who would still wall it. A Wall Breaker often just packs an immense punch, through items like Choice Band or Life Orb, and 2HKOs most switch-ins.
- Setup Sweeper: a Mon meant to use moves like Swords Dance, Dragon Dance, Aglity and so on to then shred through your opponent's team. This is a win-con for many teams. Prematurely setting up, i.e. setting up when your opponent still has switch-ins., is a common mistake even amongst more experienced players.
- Revenge Killer: a Mon coming in after one of yours has been knocked out, immediately threatening the killer and/or any possible switch-in.
- Pivot: a Mon able to scout for certain moves or sets by having U-Turn/Volt Switch, Protect, Substitute etc. Often a good lead to most teams.
- Lead: The Pokémon you start off your battle with. Often something capable of setting up weather or entry hazards.
- Phaser: a Mon meant to do Phasing, a strategy where you use moves like Whirlwind, Dragon Tail, Roar etc. to force your opponent into unfavorable matchups, forcing them to switch into a favorable one, which you can then phase out again. Also used to reset set-up move stat boosts.
- (Entry) Hazards: Any one or combination of the following; Spikes, Stealth Rock, Toxic Spikes, Sticky Web. Amongst many experienced Smogon players, Stealth Rock is referred to as the most broken move in the game. Competitive Pokémon is very much about forcing switches, predicting them, finding favorable match-ups and thereby openings to sweep etc. Entry hazards punish these switches, the extent depends on the respective type of hazard and switch-in.
- Spinner: a Mon designated to using Rapid Spin in order to keep entry hazards from your field.
- Defogger: a Mon designated to using Defog in order to keep entry hazards from your field. This also removes any hazards on your opponent's side.
- Spin Blocker: a Mon meant to switch in to a Spinner in order to block its Rapid Spin. Opposed to Defog, Rapid Spin is an attacking move and as it is Normal type, it can be blocked by Ghost Pokémon. You could also refer to Pokémon with Sticky Barbs/Rough Skin & Rocky Helmet as a type of spin blocker, but they do not directly make the move miss, but rather punish the Spinner severely for using it repeteadly - thus blocking it indirectly.
- OHKO: One Hit KO
- 2HKO: Two Hit KO, often the deciding criteria of whether a Pokémon is capable of switching in, especially if the attacker is fast, as a 2HKO basically means it cannot switch in.
- (Death) Fodder: the act of sacrificing a Mon for a certain purpose, e.g. getting a free switch into something else, without having it take a hit. Foddering also refers to switching the Mon into lethal entry hazard damage
- Scarfed/Banded/Specs/Choiced: a term to describe a Pokémon carrying Choice Scarf/Band/Specs and being locked into the first move it uses before switching.
- Speed Tier: refers to the Base Speed Stat the Mon X has, which determines which Mons it can and cannot be faster than. Speed Tiers are game-deciders for whether a Pokémon is a suitable Sweeper, Revenge Killer etc.
- Coverage: refers to the amount of types and dual types your Pokémon can hit super effectively. Moves like Hidden Power Ice, Hidden Power Fire, Ice Punch/Beam, Fire Punch, Flamethrower are very common (Bug+Steel, Grass+Steel, Dragon+Ground, Dragon+Flying, ...) but also Poison Jab, Stone Edge, ... can all be referred to as Coverage.
- STAB: refers to a 50% increase in damage when a Mon uses a move of its own type. Adaptability raises this to 100% increase. STABs generally, with some exceptions, majorly define your Pokémon's moveset and overall viability.
- Priority: refers to move order regardless of speed stats. When 2 moves/actions are of the same priority, they are then decided by speed stats. E.g. Aqua Jet has priority +1, so even the slowest Mon will hit its Aqua Jet before e.g. Deoxys Speedgoing for Spikes. However, moves like Extreme Speed are of +2 priority and thus will always hit before moves like Aqua Jet. There are also moves with negative priority, for example Whirlwind or Trick Room. Same principles apply here. Switching has the highest priority.
- Clause: a proposed rule to benefit the healthiness of a certain tier. E.g., a common Smogon clause is the Sleep Clause, used in all its tiers except AG (Anything Goes), which limits the amount of Pokémon you may put to sleep at the same time to just one. Your teams need to obey these Clause rules if you want to participate on Showdown ladder play, and making a move that violates those rules will fail, basically skipping your turn - e.g. if you try to use Spore on a switch-in, while you already put another opposing Mon to sleep.
This covers alot of terms, though there's still some more which I will spare you from here.
Now, as I mentioned
"unwritten rules" beforehand, here is an example list of them. They give a sort of
"first glance checklist" to evaluate whether a team even stands some sort of chance against other competitive teams. Keep in mind, they always depend on the meta:
- have a Stealth Rocker, optional: Spikes and/or Toxic Spikes
- have 1-2 proper Leads, i.e. Pokémon that can safely be brought out first to set up weather, entry hazards or pivot. These depend on the meta. Common OU leads atm need to be able to check Landorus-Therian, Greninja, Pelipper, Tapu Koko, ... to name a few
- have a 'Scarfer', i.e. Mon carrying a Choice Scarf. This is to prevent being right out swept by a fast opposing Pokémon. Scarfers make for excellent revenge killers, due to their outstanding speed. Regular speed tiers to see carrying Scarf are 100 Base Speed or more.
- have a Mega Evolution. This is by no means neccessary, but Megas tend to be amongst the strongest in their respective tier, or at least very strong and viable competitors.
- have a Mon carrying a Z-Stone. Also not neccessary, but Z-Stones are the reason some Mons are even viable. E.g. Gyarados is only still playable in OU as it can use Bounce for a strong Supersonic Skystrike after being +1 from Dragon Dance to knock out a Mon otherwise checking it, granting it a Moxie boost to now sweep with +2 Atk +1Spe. There are many other examples, like Latios carrying Z Electrium to boost Thunderbolt in order to severely weaken/kill Celesteela and Toxapex, Landorus-Therian with Fly and Flynium Z for Tangrowth and Ferrothorn and others, ...
- have at least one Ground immunity through the means of Levitate or a Flying type, with the prior being more succeptible to Mold Breaker which ignores Levitate.
- have something that can switch into Fairy, Dragon, Fire, Ice, Fighting moves respectively (very common Coverage)
- spread different types/coverages amonst your team. You get diminishing returns by having 3 Mons that carry Stone Edge/Rock Slide/HP Rock and might miss out on other important coverage, like Ice, Fire, Ground, Poison, ...
- have something that can switch into status afflictions without caring much, like Magic Guard Clefable, or a special attacker that can take burns, or a Steel/Poison type to switch into Toxic
- be aware of your hazard control and how much your team relies on it. If you decide to run with e.g. Charizard Y, you are forced to have at least one way to get rid of Stealth Rocks, as Zard takes 50% upon switch-in, rendering it very weak when it comes to then breaking through teams.
- have at least one set-up sweeper to break through wall heavy teams, as if your Mons don't pack the neccessary punch, Recover & Status affliction spam can easily spell death
- try to have at least one positive priority move, to prevent yourself from getting swept by fast sweepers.
- be aware of whether you need terrain control (Electric, Mystic, Psychic, Grassy) and how these affect your team, respectively. E.g. teams that use AV (Assault Vest) Magearna often like to couple it with Tapu Bulu, as Grassy Terrain gives Magearna some form of recovery, rounding that set out nicely.
- reflect your lineup regarding what team archetype you are trying to build. When going for e.g. a Balanced team, you probably want 1 Def Wall, 1 SpDef Wall, 1 Scarfer, 1 SpAtker, 1 PhysAtker, some entry hazards, some status afflictions, ... a team that has 6 Banded Mons is not Balanced, regardless of whether the Mons themselves are typical for balanced teams.
Now that you have a (very very) basic understanding of what to expect, here are some very good sources I suggest you to check out (no links allowed, just descriptions) :
- Viability Rankings of strong Mons in the smogon forums
- Common sets for pretty much every Mon and detailed explanation of why those EVs, IVs, Moves, Natures, Items, ... are used and what are common checks, counters and teammate options - just visit the smogon website and use the search function. A simple Google search like "Tyranitar smogon SM" will also lead you directly there
- A good subreddit for first hand RMTs (Rate My Team threads) and Team Showcase threads, but also general competitve Pokémon questions: /r/Stunfisk
If you have any further questions, let me know. I hope this was helpful, but I bet also quite overwhelming. Though hopefully that makes you see there is quite alot to the competitive scene. And that "unfair" legendary Mons and Ultra Beasts are probably just a tiny fraction of what makes competitive Pokémon complex, and that in fact true strength and being overpowered/"unfair" is decided by other factors. Of course, legendary Mons are still undeniably strong - hence many of them being restricted to the Ubers tier in Smogon.
