Alright can someone fill me in on what doubling down does in these types of quests? It isn't the first time that I've seen it and I'm just as confused as then.
As a longer explanation of Double Down, it is 95% of the time a good thing. You pay double for an action requiring a roll and a +20 is added to the result of the d100. So if a 67 is rolled, it becomes 67+20= 87 total. Now this +20 can only be applied to d100 rolls, but they do not need to be success/failure rolls. Most GM's allow them to be applied to rolls that are already successes, but have graded results. For example if there was an action to get tanks, the roll could be to see how many we get. Like a 100% chance to get 1, 80% chance to get 3, 50% for 5, and 10% for 10. If we applied the double down we would be guaranteed at least 3, as the lowest we could roll is a 21.
As stated, the cost of the action doubles if you double down on it, or increases by 100 if the action is free or less then 100 base. Also you can only double down on ONE action a turn, so it is important to be careful what you select. The rules for doubling down on multi-turn actions varies from GM to GM, as the need for rolls also changes from person to person. Some simply have one roll on the first turn, and it passes or fails from that. Others require a roll only on the last turn to determine pass/fail, and some need a roll for every turn the action takes. In the last case, it becomes a question if the DD price only needs to be paid once and is applied every time, freeing the DD for the next turn while still adding +20 to the original action, or a different system is in place. Some only apply the bonus for 1 turn, and if you want the bonus you need to pay it again.
Finally, there is the strategy of what to use the DD on. The most common choices are actions with low success percentages, like the option to talk to Iscariot for 30%. If we chose that and doubled down, instead of needing to roll a 70 or higher, we would only need a 50 or higher. However there are two common exceptions to this rule, the near certainties and the vitals. With near certainties, the roll is easy to pass at around 80%. If chosen we could not fail it, and we have a chance to Critical. Criticaling is when the dice roll is 96 or greater, and is normally only a 5/100 or 1/20 chance. on multi-turn actions, it cuts off a year of time, and on final turns or single turn actions results in VERY good things. For example a roll to appease the gods. A pass means they are happy, and nothing bad happens. A critical is they are very pleased, and grant a boon like an artifact or divine favor. Using the DD means it is easier at get that critical. Then there are the vitals. These are the rolls that MUST succeed, or else. For example we were just attacked and the base was near leveled. We need to find out who attacked us before they slip away. We would DD to ENSURE we know who to attack/focus our efforts on.
One final note is how the GM handles DD'ed actions that still fail. It usually comes down to either not being as bad, or WORSE. In the first case the failure is not so bad, as the +20 brought us closer to the required number, lessening the blow. For example we discover a curse has been placed on the base. A normal roll to remove it fails by 25, the curse remains and people get sick. A failed DD turned it into a failure by 5, so the curse remains but we prevent it from doing anything this turn. On the other hand some GM's punish failed DD's, so that failure from before, where we doubled down but failed, we actually made the curse WORSE, or removed it but blew up the base in the process. The GM punishin failed DD's is the possible other 5% bad thing about them.
...I think I may have tried a little to hard on this post.