Normally in 6X, whenever there's a dynamic action or dramatic twist to the plot, you make a 6-entry chart where the active player fills in one end with the ideal success result, the GM picks the most dramatic (and most appropriate) failure for the opposite end, and the rest of the players fill in one possibilities 2 to 5, half as successes and half as failures, to fill out the spectrum between these extremes. Then you roll a d6 to find out which one happens.
In this variant, we ditched the structure of a chart with exactly 6 entries. Instead, we used notecards and a paper bag (which could have been a hat, or pot, or whatever metaphor/tool you prefer). When an action or event would come along that would in vanilla 6X result in a chart and die roll, everyone scribbled down a possible result on a notecard and we threw them in the bag. One result was drawn from the bag and used, and the unused result cards discarded.
More often than not, we didn't even announce the "best" and "worst" results (the "1" and "6" results of a standard 6X chart), so the only options you knew when the cards were drawn was whatever you personally threw into the hat, plus eventually the one card that was actually pulled and read aloud.
This had several advantages over the default rules:
- Faster pacing, less downtime. Everyone writing down their results at the same time instead of sequentially meant we were less likely to get hung up by one person drawing a mental blank. If someone else was taking too long, you had the option of writing up a second result card yourself instead of sitting around bored.
- Escaping from the 50% success rate. There are times where more interesting failures present themselves than successes, and if the group overwhelming wants something to succeed or fail, it's a lot more likely to turn out as the consensus wishes. The semi-anonymous nature of cards getting dumped in the hat meant this sort of "we all want you to fail" dynamic could happen smoothly without any out-of-character social drama or political debate. Plus, if one character was meant to be a badass and the another the comic relief, they aren't both saddled by equal odds of success.
- No lame results. Unlike vanilla 6X, you never agonized over trying to come up with a "2" that was still negative, but not as bad a the "1" result. No need to put filler onto the charts. If you personally couldn't think of a cool result for that particular action, you'd just choose not to throw something into the hat this round.
- Far less confusion. Every game of 6X I've ever played had at least one event where the most memorable or amusing result on the chart was not the thing that ended up being rolled. Which then always results in somebody mis-remembering that interesting "almost-was" as if it happened, and basing later results or plot developments on something that the rest of the table realizes didn't occur. In this variant, all those other possibilities stay secret and only get revealed if they're drawn. Keeping the narrative and past events straight in your head is much easier when you're not hearing every possibility that didn't happen.
- The semi-anonymous nature of the card inputs to the hat could skew the game and/or be abused. If all the players wanted to, they could submit only successful and beneficial results, dramatically reducing the narrative tension to the point of boredom. If someone had an out-of-character axe to grind, they could get away with making every card (or rather, every card they wrote) pick on the same target disproportionately. If someone in the group has a fragile ego or a long-standing grudge, you may be better off using the more-transparent default 6X method.
- Along those lines, the option to throw in a second (or third?) card could be abused. If you find that someone keeps throwing multiple cards into the hat on roll after roll to make their own ideas more likely to be chosen, you may need to reign them in. The second card is meant to be an option for when inspiration strikes, not a way to game the system. If you are throwing in two (or more?) cards, they should be for significantly different ideas, not just to increase the odds of getting your preferred result.
- You really chew through the notecards fast. Our one-shot had 20 events worth throwing in a card, and 7 players, so we burned through around 150 half-sized notecards. A normal game of 6X would have used less than half that.
- Lastly, and certainly most sadly, you will find that some of the best material never gets revealed. At the end of the session, it may be worth digging through the piles of discarded cards to see what wonderful ideas never came to be.