In ‘The War Games’ the 2nd Doctor makes a fateful decision to summon the Time Lords. Although this resolves the problem created by the War Chief it leads to his capture, forced regeneration and exile to Earth.
How might things have gone differently if he hadn’t contacted his own people. What if he had found a solution to the problem and been able to send everyone in the various war zones to their natural time and place without the Doctor asking for help?
For the viewer the existence of the Time Lords might have remained a mystery for longer. The show runners could even have abandoned or changed this idea completely. The Doctor would continue to be a mysterious figure with only occasional encounters with others of his kind.
Most importantly, from a real world perspective, we’d have more 2nd Doctor adventures. Far to many have been lost to time and we’d be able to see the 2nd Doctor make the transition to colour.
‘The Two Doctors’ suggests that Jamie would continue as a companion for decades (unless in the fabled Season 6B the Time Lords reunited the two later in Jamie’s life). He shows steadfast loyalty and patience with the Doctor so it would take something drastic to make him leave.
Zoe is a bigger question mark. Travelling with the Doctor certainly satisfied her thirst for knowledge but she also seems the type of person who would want to achieve something permanent, rather than continually moving from place to place.
I feel that eventually she’d find a big project that she’d want to see through to completion. In much the same way that Nyssa stayed on the Terminus station to help turn it into a hospital in ‘Terminus’ Zoe would say goodbye to the Doctor to achieve a grand goal using her great intelligence.
Following the hints in ‘The Two Doctors’ the TARDIS crew might reunite with Victoria, possibly after she has had a chance to mature. An older Victoria might have a disposition more suited to travelling in the TARDIS. She might even find a way to summon the Doctor to let him know that she was ready to travel again.
The UNIT adventures experienced by the 3rd Doctor needn’t be wiped from this revised timeline. Having already encounter the Brigadier twice before the 2nd Doctor would likely look in on him, particularly as an older 2nd Doctor does just that in ‘The Five Doctors’.
Each time the Doctor could arrive at a crucial moment, whether it be the initial Auton invasion or the Masters arrival the Doctor is on hand to help. The Doctor might even be convinced to stay for a while in this time period, either by the Brigadier or his current companions.
This would be the perfect opportunity to Jamie to leave the TARDIS if he became particularly enamoured with the UNIT soldier lifestyle. ‘The Invasion’ suggested that Jamie could fit in quite nicely to the 60s (or whatever the UNIT time period is).
It would also seem natural for the Doctor to pick up a companion from the UNIT time period. This wouldn’t necessarily have to be Jo Grant or Sarah Jane Smith, although Liz Shaw would make a good replacement for Zoe.
An extended life for the 2nd Doctor could see him clashing with enemies, old and new. How the 2nd Doctor interacted with the Master could be very interesting and amusing, assuming that this was the Roger Delgado version.
By his very nature the Master believes himself to be superior. This was countered by the 3rd Doctor’s own self assurance and will power. Both at least gave the impression of being civilised gentlemen.
In contrast the 2nd Doctor can either be quite humble (to hide his true intelligence) or egotistical (declaring his genius). Encounters with the Master could result in taunts, mockery or school boy tantrums. This would have been glorious to see on the screen.
The impish character of the 2nd Doctor cries out for another encounter with the Celestial Toymaker. ‘The Mind Robber’ demonstrates how well the 2nd Doctor works in a semi-fantastical setting.
Of course the 2nd Doctor could also meet the great and terrible Zodin. Mentioned only briefly in ‘The Five Doctors’ the exact details are scarce, allowing the writers to be creative in how they interpret this adventure.
‘The War Games’ need not deviate completely from what we know. The Doctor might indeed have summoned the Time Lords but managed to escape. In this continuity the knowledge that they are pursuing the Doctor could add some continuing tension and give the viewer a reason why the Doctor is always on the move.
You might even like to introduce an antagonists, assigned to track the Doctor down. They might appear in a few adventures, so the Doctor not only has to deal with the current problem but avoid capture.
This would transform this into a ‘Man on The Run’ show along the lines of ‘The Fugitive’, ‘The Incredible Hulk’ or early ‘The A-Team’.
Would the 2nd Doctor have so many adventures that he’ll eventually become the gray-haired we encountered in ‘The Two Doctors’? Could this be the version encountered in the multi-Doctor stories? Rather than being from the past he has crossed over from another reality, explaining the apparent continuity problems his appearance creates.
In addition to the extra adventures the 2nd Doctor might experience another big change will be his regeneration. When it is eventually triggered it is unlikely that he’ll take the form that he did in the series, as that was chosen by him by the Time Lords.
From this point on the future becomes a blank slate, both in terms of what this 3rd Doctor is like and the adventures he will have. This could be a good point for a Doctor Who campaign to start, giving players the freedom to interpret the character in their own way.