Hands down, I think Yortzee is the best game on here. And although it is based strongly on Yahtzee, there are surprisingly a good number of questions surrounding how to play. So no surprise that I feel a mini guide would be a good thing.

Basics
Objective: Obtain the highest possible score by forming certain dice combinations

Gameplay:
- Use the "roll" option to get a 1-6 value on five separate dice
- You can click on a dice to lock it in for the next roll.
- Three re-rolls can be done before you are forced to choose a scoring option.
- The scoring options in the table can only be used once each.
- Game ends when no more scoring options can be used.

Scoring
* numbers (Ones, Twos...etc.): only adds up dice with that number value
* Three of a Kind: adds up all dice if at least 3 of them have matching values
* Four of a Kind: adds up all dice if at least 4 of them have matching values
* Full House: 25 pts, if 3 match and 2 match
* Small Straight: 30 pts, if 4 dice contain a sequence
* Large Straight: 40 pts, if all 5 dice contain a sequence
* YORTZEE: 50 pts, all dice match
* Chance: adds all dice up
* Bonus: 35 points added at end, for getting YORTZEE a second time

Strategy
The two most overlooked aspects are rerolling and locking. They are the basis of strategy, amidst the random nature of the game.

Now the goal of Yortzee is obviously to get as high a score as possible, but that is done through short-term goals. The main goal is to get YORTZEE--but on every roll, the immediate goal should be to use up a scoring option. And well. The earlier you get YORTZEE the better, because as the game progresses, there's lower chance of getting it due to urgency of hitting the varying scoring options, and more often than not, it is not rolled. Officially, there is something around <5% likelihood of rolling it.

YORTZEE, Full House, and the two Straights should take priority over anything else. In other words, use them first because their point values are not variable.

Thus,
YORTZEE > Large Straight > Small Straight > Full House > anything lower than 25

In other words, the right column takes precedent over the left column.

Be sure to think about each option, about which will score highest, and if things like 3 in a Row should be saved for later. For example, rolling 3 sixes only means 18 for the 3 in a Row. Don't pick that option yet, lock them up, and try to get something worth 20+, if available.

Try to max numeral scoring options after finishing (most of) the special combos on the right. Don't settle for just a few points, but do remember each option can only be used once, and you must use one up per turn. Optimally, the 3, 4, 5, and 6 options should be decent numbers. So if one of them is just flat 0 or a measly 6, you might be better off starting anew.

Don't be too quick to use up the "Chance" option. It should be a last resort, and recommended for use when dice equal 20 or more. It may be even a better choice to sacrifice a low number option like 1 or 2 with a scoring output of 2 or 3 to save Chance. Sometimes, it is the key to getting up there.

Rolling Full House can be tricky. Typically, it is done after finishing off 3 in a Row, unless the 3 in a Row was poor output, e.g. 9 pts. Say you did get 3 threes; lock them, then keep rolling and hope the remaining open two match up--the chances are decent.

However, going for Full House is sometimes not a good idea. Usually, this is for the Straights. Getting a few close values like 2 twos, 1 three, and 1 four, go for a straight. Large always takes priority over Small.

Keep approximate probabilities in mind. You have 3 matching, consider whether to add 'em up now, or try all out for a YORTZEE. More aggressively pursuing YORTZEE is generally not a winning strategy, as it tends to either come out of the blue, or from a 3- or 4-matching on the first roll.

Don't overlock. Keep your options open.

Other hints
If you get 300 points, you get a Yortzee badge on your profile. This is the most common goal.

If you are aiming for the high scores, it is pretty important to hit YORTZEE and then get a second with Bonus. This is very difficult, but should always stay in the back of your head.

Hitting YORTZEE doesn't guarantee anything, even if early, (it is only 50 pts, 1/6th of 300) so keep playing methodically for a good score.