Here are some Yu-Gi-Oh cards that force your opponent to discard cards from their hand:
Monsters:
* D.D. Crow: Destroys a monster on the field, then your opponent discards a card from their hand at random.
* D.D. Warrior Lady: Destroys a monster on the field, then your opponent discards a card from their hand with the same name as the destroyed monster.
* Effect Veiler: Negates the effect of a monster on the field and forces your opponent to discard 1 card.
* Swords of Revealing Light: Reveals your opponent's hand. They must discard all cards that have the same name as any monster on your field.
* Forbidden Lance: Destroys a monster on the field. Your opponent discards a card from their hand for each monster you control.
* Ghost Ogre & Snow Rabbit: If your opponent activates a Spell/Trap card, you can discard this card to negate its activation and banish it.
* D.D. Crow Tengu: Destroys a Spell/Trap on the field, then your opponent discards a card at random.
* The Phantom Knights of Break Sword: If your opponent activates a card, you can banish this card from your GY to negate its activation and destroy that card. Then, your opponent discards a card.
Spells:
* Pot of Greed: Draw 2 cards. (Limited to 1 per duel)
* Card of Safe Return: Draw 2 cards. (Limited to 1 per duel)
* Heavy Storm: Destroy all Spell and Trap cards on the field. Then, each player discards a card.
* Raigeki: Destroy all monsters your opponent controls. Your opponent discards a card.
* Torrential Tribute: Destroy all monsters on the field. Each player discards a card from their hand.
* Mystical Space Typhoon: Destroy a Spell/Trap card on the field. Your opponent discards 1 card.
* Twin Twisters: Destroy 2 Spell/Trap cards on the field. Your opponent discards 1 card.
* Forbidden Chalice: Choose 1 monster on the field. Its effects are negated. Your opponent discards 1 card.
Traps:
* Call of the Haunted: Special summon a monster from your GY. Your opponent discards a card.
* Wasteland: All players discard their hands and draw a new hand of 3 cards.
* Solemn Warning: Negate the activation of a Spell/Trap card and destroy it. Your opponent discards a card.
* Compulsory Evacuation Device: Destroy a monster on the field. Your opponent discards a card.
* Royal Decree: Prevent your opponent from activating Spell/Trap cards. Your opponent discards a card.
Other:
* Chaos Sorcerer: If this card is sent to the GY from the field, you can discard 1 card to special summon this card. Then, your opponent discards 1 card.
Important Considerations:
* Some of these cards have restrictions on their use, such as limitations on the number of copies you can use per duel, or specific conditions that must be met before you can activate them.
* There are also other cards that can indirectly force your opponent to discard cards, such as those that destroy monsters or banish cards.
This is not an exhaustive list, as there are many other cards that have discard effects. But these cards are some of the most common and effective ways to make your opponent discard cards in Yu-Gi-Oh.
Remember to always check the card text carefully to understand the specific effects and restrictions of each card.