Båda

Wands arbetar genom att kanalisera magi. När tappen är trasig upphör den att vara en effektiv kanal.

The holly and phoenix wand was nearly severed in two. One fragile strand of phoenix feather kept both pieces hanging together. The wood had splintered apart completely. Harry took it into his hands as though it was a living thing that had suffered a terrible injury. He could not think properly: everything was a blur of panic and fear. Then he held out the wand to Hermione.

‘Mend it. Please.’

‘Harry, I don’t think, when it’s broken like this –’

‘Please, Hermione, try!’

‘R – Reparo.’

The dangling half of the wand resealed itself. Harry held it up.

‘Lumos!’

The wand sparked feebly, then went out. Harry pointed it at Hermione.

‘Expelliarmus!’

Hermione’s wand gave a little jerk, but did not leave her hand. The feeble attempt at magic was too much for Harry’s wand, which split into two again. He stared at it, aghast, unable to take in what he was seeing … the wand that had survived so much…
Deathly Hallows - Chapter 18: Bathilda’s Secret

(betona min)

I Secrets Chamber , när Ron sätter på sig, har han (och Lockhart) stora problem att använda den.

‘My wand,’ said Ron, in a shaky voice. ‘Look at my wand.’

It had snapped, almost in two; the tip was dangling limply, held on by a few splinters.
Chamber of Secrets - Chapter 5: The Whomping Willow

Ron plunged his hand into his robes, pulled out his wand, yelling, ‘You’ll pay for that one, Malfoy!’ and pointed it furiously under Flint’s arm at Malfoy’s face.

A loud bang echoed around the stadium and a jet of green light shot out of the wrong end of Ron’s wand, hitting him in the stomach and sending him reeling backwards onto the grass.
Chamber of Secrets - Chapter 7: Mudbloods and Murmurs

[Lockhart] raised Ron’s Spellotaped wand high over his head and yelled, ‘Obliviate!’

The wand exploded with the force of a small bomb. Harry flung his arms over his head and ran, slipping over the coils of snake skin, out of the way of great chunks of tunnel ceiling which were thundering to the floor. Next moment, he was standing alone, gazing at a solid wall of broken rock.

‘Ron!’ he shouted. ‘Are you OK? Ron!’

‘I’m here!’ came Ron’s muffled voice from behind the rockfall. ‘I’m OK. This git’s not, though – he got blasted by the wand.’
Chamber of Secrets - Chapter 16: The Chamber of Secrets

Så eftersom brutna väggar fungerar inte bra, verkar det som helhet syftet med ett snurrande ceromoni att vara funcitonal i naturen.

Men eftersom häxan eller trollkarlen helt enkelt kunde hitta en annan trollstav om de ville ha, eller kanske vara skicklig i trolllös magi, ser det ut som att bruden av tappen också är ceremoniell.

Ägare kan styra sina wands från ett avstånd

När dementorerna attackerade Harry och Dudley behöll Harry viss kontroll över sin trollstav, även när den skilde sig från det:

'Where’s – wand – come on – lumos!'

He said the spell automatically, desperate for light to help him in his search – and to his disbelieving relief, light flared inches from his right hand – the wand-tip had ignited. Harry snatched it up, scrambled to his feet and turned around.

— Order of the Phoenix, Chapter 1: Dudley Demented

Även om effekten i detta fall var liten, kan Harrys mottaglighet för Dementors påverkan ha varit ett problem. Under idealiska förhållanden kan en häxa eller trollkarl kunna utöva starkare kontroll över större avstånd.

Behållande vingar som bevis

Om någon använder en trollstav för att kasta en oförlåtlig förbannelse - som Crucio för att torturera Aurors - kan lagen kräva att myndigheterna behåller tappen (med skyddsåtgärder, förstås) för senare utredning. I andra fall som Hagrids - han anklagades inte för att använda sin troll direkt för att orsaka den skada som han (orättvist) utvisades - det skulle inte vara nödvändigt för myndigheterna att hålla trollen intakt.