Let's call this the License Plate Game, because that's the easiest place to get three nearly random letters. You start with three given letters, and you have to make them into a word. And you start with eight points.
If you add one (or more) vowels to the beginning or end of the letters, that costs you one point. Or if you have to add one or more consonants to the beginning or end of the letters, that also costs you a point. If you have to add some (one or more) vowels and also some consonants, your score is down from eight to six points. It doesn't make any difference how many letters you add. But that's just the start.
If you have to change the order of the given letters to turn it into a word, that costs you two points. And/or if you have to insert any new letters into the original letters, that costs you two more points. So if you have to do all those things, you are down to just two points. But if you can't make any word at all, then it's not too surprising that you get zero points.
You can see that this is not at all like sudoku, where every move is just logical. In this game, you have to be able to manipulate letters and make words. And as a first hack, I'd say the scoring is based on elegance.
Now, that isn't the end of the scoring. Let's say that by using those rules and procedures, you can make a word that's worth six points, or whatever. But you can win one bonus point if you can take the given letters and make one word using only added vowels and make one word with only added consonants. And that is a nice little challenge. I think it's fun. I got the concept of this game from an old friend, Karen, but she started with six points. I think eight is fairer.
There is one more side rule. If the three given letters already make a word, that doesn't count. You have to change or add something to make some new word. Now, there may be only 203 combinations of letters that will show up on license plates. But that's pretty good. 8000 is enough. Note that "ABC" is not the same as "CBA" or "BCA," so it's not too boring.
How can two or more people play in a competitive way? I haven't really thought of any firm rules, but obviously you have to have some plans for allowing enough time for all the players to find a word or words. Then at a suitable time, somebody has to decide who states his solution. Maybe the player with the highest number of claimed points goes last. What words are considered legal? Well, you can set your own house rules and pick any dictionary you choose. Myself, I tend to accept plurals, but not proper names, such as geographical places.
Here's an example. RED is already a word, and you can easily-make REED or REND. However, those involve splitting the original letters, so those would make just five points. Therefore, SHRED is better, as it does not involve splitting. And those seven points, added to the bonus point (for the one word you made by only adding consonants, and the other word you made by only adding vowels) brings you back to eight.
When there are awful combinations like JXZ, you concede quickly and go on to the next car—the next set of letters. At least, I can't make a word with J, X, and Z. If you find any combinations of letters that seem hard, send them to me as a challenge!
Disclaimer: This game specifically is not recommended for drivers, who may get distracted and forget where they need to turn off or when they need to put on the brakes. Avoid playing this game if you get distracted.