Hoď kostkou.

Hoď is the singular informal imperative of the verb hodit.

• hodit = to throw, toss, cast; in this context, to roll
• hoď! = roll! / throw! said to one person you address as ty

So Hoď kostkou. is a command to one person: Roll the die.

In Czech, commands usually do not need an explicit subject.

So instead of saying Ty hoď kostkou, Czech normally just says:

• Hoď kostkou.

Adding ty is possible, but it gives extra emphasis, contrast, or emotion, for example impatience:

• Ty hoď kostkou, ne on. = You roll the die, not him.

The basic, neutral version leaves you unstated.

Because kostkou is the instrumental singular form of kostka.

The basic noun forms are:

• kostka = nominative singular
• kostkou = instrumental singular

In the expression hodit kostkou / házet kostkou, Czech uses the instrumental case. This is simply the normal pattern for this gaming expression.

So learners should remember it as a set phrase:

• hodit kostkou = to roll a die
• házet kostkou = to be throwing/rolling a die

Not quite.

• Hoď kostkou is the normal way to say roll the die in a game.
• Hoď kostku would sound more like throw the die / throw a cube as an object.

So the case changes the meaning:

• instrumental: kostkou → the standard gaming expression
• accusative: kostku → a more literal direct object, as if you are throwing the object somewhere

This is a very useful distinction to learn as a chunk.

The dictionary form is kostka.

In game contexts, kostka means die. More literally, it can also mean cube.

So depending on context, kostka can be:

• a die
• a cube
• sometimes things like a sugar cube or ice cube

But in Hoď kostkou, it clearly means a die.

This is about aspect, which is very important in Czech.

• hodit = perfective → one complete action
• házet = imperfective → repeated, ongoing, or habitual action

In a board game, if you want someone to make one roll now, Czech naturally uses the perfective imperative:

• Hoď kostkou. = Roll the die.

If you said:

• Házej kostkou.

that would sound more like:

• Keep throwing the die
• Throw the die repeatedly
• or a more ongoing/repeated action

So for a single turn in a game, hoď is the natural choice.

You would use the plural/formal imperative:

• Hoďte kostkou.

This can mean:

• Roll the die. said to several people
• Roll the die. said politely/formally to one person

So the contrast is:

• Hoď kostkou. = singular informal
• Hoďte kostkou. = plural or polite/formal

Si adds a slight sense of doing it for yourself, and in game situations it can sound very natural, like:

• Go ahead and roll the die
• Take a roll

So:

• Hoď kostkou. = Roll the die.
• Hoď si kostkou. = Roll the die / Have a roll.

In many contexts, both are possible. The version with si can feel a bit more conversational or game-like.

Yes, but Hoď kostkou. is the neutral, standard order.

You could also hear:

• Kostkou hoď.

But that would usually sound marked or emphatic, for example if contrasting it with something else:

• Kartou ne, kostkou hoď. = Not with the card, roll the die.

So for normal learning and normal use, stick with:

• Hoď kostkou.

A rough guide:

• Hoď = one syllable, with a soft ď
• kostkou = roughly KOST-kou

A few useful notes:

• ď is a soft Czech d sound, not the same as a plain English d
• ou is a diphthong, somewhat like the vowel movement in English go, though not exactly the same
• stress in Czech is normally on the first syllable, so:
  • HOĎ KOST-kou

You do not need to pronounce it dramatically; just keep the first-syllable stress and the soft ď.