One of the toughest achievements in this game. You need to score only 5 points total in Classic game mode. (I tried Battle mode, didn't work. Other modes are even tougher to get only 5 points, so I didn't even try).
You can play using the "Play Now" option, and is better to do so, because you play solo. There is no reason to play with 2 players, because you will certainly lose, and only wins count for the other achievements.
The basic premise is: You must score a Yahtzee made of ones (5x1). Nothing else. And that Yahtzee needs to be scored in a chance spot (marked by "?"). Because if you don't, the game forces you to play a chance anyway and adds your dice to the score.
This is where you need a bit of strategy.
The strategy is the following:
- The first chance you get and roll no 1s, block off the 1 tile in the upper section.
- Next, block off "3x" and "4x" tiles in the lower section.
(This is done because your objective is to collect 1s. If you don't do this as fast as possible, you might be forced to actually score these tiles later on.)
- Once that is done, block off upper section numbered tiles as the chance arises (i.e. you have no dice of that number).
- Full House, Small and Large Straight tiles should be used in dire need when you have no free numbered dice.
- Yahtzee field should usually be left for last, as it's the least likely to actually happen.
NOTE: You know which tiles have a zero score because they lack a white border and have a dash underneath them. If they are bordered, don't use them, you will score.
The last part of the achievement is left to sheer luck:
- You actually need to score a Yahtzee made of 1s.
Basically, using this strategy, you have 13 chances per game to get it, and if you follow it, you will get the achievement.
It took me about 25-30 tries. I got the achievement mid-way through the game, then I just rolled once per try and filled in the blank spots as necessary.
Good luck!