What it does
Light Ball is exclusive to Pikachu, and its effect is one line but brutal: it doubles Pikachu's Attack and Sp. Atk at the same time. Both stats, x2 — not one or the other — which means it works whether you build Pikachu physical or special. Either way, its damage output simply doubles.
What does that mean in practice? Pikachu's base Attack and Sp. Atk are both low — it's a textbook frail mascot. But double both, and its effective offense jumps to the level of a frontline attacker. A Pikachu that looks harmless can knock out a frail target in one hit and even punch through some semi-bulky ones. Opponents who don't know you're holding Light Ball tend to underestimate it — and find out the hard way after the first hit lands.
The limits to keep in mind: Light Ball only works on Pikachu — give it to anything else and it does nothing. It also doesn't touch Pikachu's bulk. Only the two offensive stats double; HP and defenses are still that same frail mascot. So Pikachu stays a glass cannon: it hits hard, but it breaks.
Who runs it
There's exactly one answer here: Pikachu (60%). Light Ball is its signature item, on over half its sets, because it's the only switch that flips Pikachu from "cute" to "actually deals damage." Without it, Pikachu's offense is too soft to see competitive play; with it, it earns a spot as a real damage threat.
Pikachu's Speed isn't bad, and paired with the doubled offense it can play a fast burst attacker in doubles — strike first for big damage, let a teammate clean up. The frailty is innate and Light Ball doesn't fix it, so Pikachu leans on teammate support to stay on the field.
How to use it
Doubles is Pikachu's home. The strongest Light Ball Pikachu lines pair its burst with support moves:
Fake Out: a Fake Out from Pikachu or a partner flinches a target so it can't move, and Pikachu fires its doubled damage safely in that window. Turn-one Fake Out plus Pikachu offense is a classic doubles opening.
Volt Switch: deal a doubled hit, then Volt Switch out — you get the damage and pull your frail Pikachu back to safety, then bring it in again later for another burst. This patches Pikachu's poor bulk and inability to linger.
Nuzzle: Pikachu's Nuzzle does chip damage and paralyzes the target. That gives your team a speed edge (paralysis halves their Speed) and sets up your own burst — lock one down with Nuzzle, then focus fire.
The through-line: Pikachu is frail but hits hard, so you use support moves to create safe windows where it can land that doubled hit without taking damage back.
Tips & strategy
Light Ball Pikachu's power rests entirely on that doubling, so your whole game plan should revolve around protecting Pikachu and making windows for it to attack. It isn't a Pokemon that trades blows head-on — it's a burst point that needs teammates to clear the road.
Once the opponent realizes your Pikachu has Light Ball, they'll prioritize removing it, because nobody wants to eat a doubled hit. So Pikachu often needs to look like a minor threat, or attack on a safe rhythm through Fake Out and Volt Switch rather than charging in. Treat it like a sharp but brittle knife: pick the moment for a killing strike, and never ask it to block.