this has been something i have been thinking of late. In the Ghost busters rpg that was made back in the 80,s they had a randommizer die called the ghost die it was a d6 with the no ghost symbol on one side if 1-5 you added it to your total. but if you the no ghost something would happen it depends what your total was if you did well it would be good if you rolled badly it would be bad. example you are trying to eat a telephone you roll the no ghost but did well on the roll you eat the telephone but it rings on the way down giving you a shock. you role the no ghost and do bad on the roll the phone receiver gets stuck in your mouth and you have to go to the hospital. if you did not roll the no ghost you did not have anything strange happen. Also it helps the bad guys when the gm rolls the no ghost. how could you apply this to Dr Who: Adventures In Time & Space i was you could have the tardis on the d6 instead of the no ghost
Well, it is already covered in the task resoultion by how much you succeed or fail a roll by.
However, for doing things that don't require a skill roll - you could use a randomising die roll there to work out whether it it's a good/bad thing.
I'd use the FATE RPG dice mechanic for that - roll a black and a white d6, make the black d6 negative, and the white d6 positive. Add the two together to give you a range of -5 to +5 which averages at 0. You could then determine how well or how badly the outcome of the event is.
You could use that for any task that isn't a) skill related or b) relevant to the plot. Because there are already system mechanics in place for both (task resolution, and the GM decides)
Similar mechanics abound all over the place. 7th Sea had exploding dice (not literally, but that would've been fun), a few games had open-ended rolling where if you rolled the highest (or lowest) you'd keep going. I loved the Ghost Die (still have one).
The best game with this sort of mechanic, for me, was a little-known gem called "Shattered Dreams". It used d12 for everything and the players would roll 2d12 for their actions. 1d12 was a normal one, the other had 3 different colours - black on 4 sides represented the nightmares, red the players and blue the dreamer whose dreams they were inside. You rolled the die and coloured in the faces appropriately when you started playing.
I like the random element these things throw in - yes, you succeeded in sneaking past the Cybermen but...
Just remember who’s standing in your way, remember every black day I ever stopped you and then—AND THEN—do the smart thing: let somebody else try first.
I don't use this for skill checks but when a question in the game arises that is not DIRECTLY relevent to the plot and its not answered by my notes I roll 1d6 and check this table...
1-2 Result is the most obvious or likely outcome 3 Result is mildly bad or unhelpful for the players 4 Result is VERY bad for the players 5 Result is SURPRISING! Not impossible but unlikely. Could be good, could be bad. But always memorable, entertaining, and thought provoking. 6 Result is best likely outcome for the players.
So if a PC decided to stop and search a kitchen for anything interesting...
1-2 Usual kitchen stuff 3 Rats that cause them to scream alerting nearby Slithene hunters 4 One of the Slithene gets the drop on the PCs while they are searching. 5 The entire refrigerator is filled with jelly babies - and all the orange ones have been removed. 6 Several bottles of vinegar and a kids super-soaker (its a Slithene story).