BW mechanics overview

This page aims to list the most important mechanics introduced in the fifth generation, which began with the Black and White versions, released in North America in March 2011, followed a year and a half later by the Black 2 and White 2 versions in October 2012. Unlike what you'll find on the BW Banlist page, everything here is directly tied to the games' core mechanics and do not depend on some specific community rules. Therefore, everything described below applies both on cartridge and simulators.

Team Preview

Unlike in the first four generations where the opposing team’s Pokémon remained unknown until they were sent out for the first time, Generation 5 introduced the Team Preview, allowing players to see the opposing team before the battle even begins. Team Preview also means that the lead is no longer determined during teambuilding, but instead at the very start of the match. The first turn begins once both players have selected their respective leads.

Hidden abilities

In addition to their regular ability (or abilities), Pokémon now also have a so-called Hidden Ability, meaning that it cannot be obtained through normal capture methods. From a competitive standpoint, some of these abilities are completely useless. The following ones are those that have seen a competitive use at some point, whether in Generation 5 or later (click on an ability for more information):

Pokémon	Hidden Abilities
	Analytic
	Chlorophyll
	Drizzle
	Rain Dish
	Prankster
	Magic Guard
	Imposter
	Moxie
	Multiscale
	Rough Skin
	Regenerator
	Technician
	Reckless
	Sheer Force
	Poison Heal

Ability Changes

Sturdy

Whereas the ability Sturdy previously only prevented a Pokémon from being hit by OHKO moves (Sheer Cold, Fissure, Guillotine, and Horn Drill), it now also prevents the holder from being knocked out in one hit while at full HP. Its effect is identical to Focus Sash, except that, unlike the item, it activates every time the Pokémon returns to full HP during a match.

Magic Guard ability and paralysis

In Generation 4, a Pokémon with the Magic Guard ability could not be fully paralyzed, although it was still affected by the Speed drop. This is no longer the case in Generation 5.

Synchronize and poison

In Generation 4, a Pokémon with the ability Synchronize that was badly poisoned by Toxic (-1/16 of its max HP on the first turn, then -2/16, -3/16, and so on) would only inflict a regular poison status condition to the opponent (-1/8 of its max HP per turn). In Generation 5, it correctly passes on a Badly poisoned status condition instead.

Lightning Rod and Storm Drain

These two abilities respectively grant an immunity to Electric- and Water-type moves, while also raising the Pokémon Special Attack stat by one stage.

Move Changes

Curse

Previously typeless, the move Curse is now Ghost-type.

Explosion and Self-Destruct

Explosion and Self-Destruct no longer halve the target’s Defense during damage calculation, which made them far less common than they were in the first four generations.

Wish

Heals the Pokémon's HP for an amount equal to 50% of the user’s maximum HP rather than the recipient’s. Thus, if a Chansey (with 704 HP) uses Wish and a Garchomp (with 357 HP) receives it, the latter will recover up to 352 HP, which is nearly its entire HP bar.

Taunt, Encore and Mental Herb

Taunt and Encore now always last exactly 3 turns, and a Pokémon holding a Mental Herb negates their effects (single use, consumed after activation).

Trick

If a Pokémon uses Trick and receives a Choice item while already holding one, it is no longer locked into Trick on the following turn, unlike in Generation 4.

Rotom form types

The various Rotom forms, aside from its base form, lose their Ghost typing in favor of a type specific to each form. However, they retain their Electric typing. Thus:

• Rotom Wash gains the type.
• Rotom Heat gains the type.
• Rotom Frost gains the type.
• Rotom Fan gains the type.
• Rotom Mow gains the type.

Sleep

[Sleep inducing moves were banned from BW OU on December 26, 2019.]

Sleep turns are reset when the Pokémon is switched out, and a Pokémon now remains asleep for only 1 to 3 turns (instead of 1 to 4 turns in Generation 4).

Life Orb

If the holder of a Life Orb attacks a Pokémon behind a substitute, it now takes the 10% recoil damage caused by the item.

Crash damage

If a Pokémon uses a move such as High Jump Kick, it loses half of its HP max if the move fails, whether due to accuracy or because the target is immune to it. In Generation 4, the recoil damage caused by a miss was equal to half of the target’s max HP if the target was immune to the move, and otherwise equal to half of the damage the move would have dealt. In Generations 2 and 3, if the move failed because of the target’s immunity, the user took no recoil damage.

Summary

A red box means that the feature is absent from that generation, while a green box indicates that it is present.