Sonic Screwdriver

Lore & Background

Throughout the programme's history, the sonic screwdriver has evolved significantly in design with each new Doctor. It was first used by the Second Doctor in Fury from the Deep, appearing again in The Dominators and The War Games. During the Third Doctor's tenure, producer Barry Letts limited its use to prevent over-reliance, leading to various design changes including a unique red spherical head prop in The Three Doctors due to the original prop going missing during Carnival of Monsters.

By the Fourth Doctor's era, under producers Philip Hinchcliffe and later Graham Williams, usage fluctuated between being downplayed and becoming central again during the Key to Time saga. In 1982, during The Visitation, the device was destroyed by a Terileptil, leading the Fifth Doctor to refuse a replacement. It returned in the 1996 movie before a full revival in 2005, maintaining continuity through data retention even when models were destroyed.

Reader's Guide

The sonic screwdriver operates using sound waves, radiation, wavelengths, frequencies, signals, and electromagnetism. It can hack, disable, and activate technology, allowing remote control of machinery and computers. Specific functions include opening locks, detonating explosives, regenerating cut barbed wire (setting 2428B), darkening eyeglass lenses into sunglasses, and conducting medical scans. It can also intercept teleportation, perform calculations to interface with wood, and create force field waves when used in tandem with other sonic devices. However, it cannot affect wood or isomorphic controls without special calculations, nor is it designed to kill living organisms, though it can incapacitate them via painful sound bursts or energy waves.

Did You Know?

• The sonic screwdriver was used as a welding torch in Episode Five of The Dominators (1968).
• In 'Day of the Doctor,' calculations started on the Tenth Doctor's sonic were completed by the Eleventh Doctor's model.

Origins and Narrative Evolution

The sonic screwdriver made its debut in the 1968 serial Fury from the Deep, written by Victor Pemberton. It was utilized during the Second Doctor's tenure in The Dominators (where it served as a welding torch) and The War Games. During the Third Doctor's era, producer Barry Letts restricted its use to avoid writers becoming over-reliant on it, resulting in significant design variations, including a one-use red spherical prop in The Three Doctors due to the original missing during Carnival of Monsters. Under Philip Hinchcliffe, usage decreased further until Graham Williams revived it for the Key to Time saga. By 1982, in The Visitation, the device was written out permanently after being destroyed; the Fifth Doctor declined a replacement. It reappeared briefly in the 1996 TV movie before making a full return in the 2005 series continuation.

Design Iterations and Continuity

As subsequent Doctors appeared, the sonic screwdriver's design changed to reflect their personalities, though it retained its core data and usage capabilities even after destruction. Not all incarnations used it on screen; the Fifth Doctor opted not to replace his after The Visitation. In a notable continuity event, the Twelfth Doctor lent his device to Davros in his childhood, losing it permanently. After using sonic sunglasses temporarily, he received a new screwdriver from the TARDIS in the final episode of Series 9. The device has been destroyed multiple times, yet each new model maintained the functionality of its predecessors, ensuring continuity across different eras.

Technical Capabilities and Limitations

The tool's functions are based on control over sound waves, radiation, and electromagnetism, allowing it to unlock doors, cut substances, detonate explosives, hack ATMs, and perform medical scans. It can amplify X-rays, regenerate barbed wire, darkening lenses into sunglasses, and create force fields with other sonics. Specific settings include 2428B for regenerating wire. The War Doctor used calculations to make it work on wood, a feat completed across the Tenth and Eleventh Doctors' models. While capable of defensive blasts that incapacitate via sound or green energy waves (seen with the Eleventh and Twelfth Doctors), it is strictly non-lethal and cannot interface with wood or isomorphic controls without advanced calculation.

Shared Utility and Spin-Off Legacy

Despite the Doctor's claim not to entrust his screwdriver, he has loaned or gifted them on several occasions. He lent one to his doppelgänger in 'The Rebel Flesh' and provided Rory Williams with one in 'A Good Man Goes to War,' 'The Big Bang,' and 'The Girl Who Waited.' Sarah Jane Smith and Rose Tyler borrowed it in 'School Reunion' before Sarah Jane received a custom Sonic Lipstick. River Song was gifted a model in 'The Husbands of River Song,' which the Tenth Doctor later used in 'Forest of the Dead.' Spin-offs expanded this legacy: The Sarah Jane Adventures featured the sonic lipstick, while Torchwood utilized devices like the sonic blaster, probe, modulator, and cane.