multi sig's one user died

[cafter]

what if a multi sig wallet is there and that required 3 person's to sign, and suddenly on person of them die or anything unusual happen, then how can we access the wallet and move funds?
and multi sig also require one seed phrase to import wallet? and how to make another wallet from multi sig to 2 person sig?

[Charles-Tim]

If you are three, you can make it 2-of-3 multisig setup. If it is 3-of-3 multisig and one of you has no access to his seed phrase again, that means the coins is lost because the three of you needs to sign the transaction generated on the 3-of-3 multisig wallet, unlike 2-of-3 that requires just two among you three to sign any transaction generated.

If you are 3, having 2-of-3 multisig, you will need your seed phrase and the other two master public keys (from the other two persons) to setup the wallet again during importation. But just 2 person that have the multisig wallet setup can use it to spend.

So if anyone among you lose his seed phrase in 2-of-3 multisig, inform the other two persons. Setup new 2-of-3 multisig wallet and move the bitcoin to the new wallet. That won't be possible with 3-of-3 as the 3 of you need to sign the transaction before broadcasting it for recovery.

I hope you understand this with other multisig wallet setup.

[nc50lc]

what if a multi sig wallet is there and that required 3 person's to sign, and suddenly on person of them die or anything unusual happen, then how can we access the wallet and move funds?

Since it's "3-of-N MultiSig", without the 3rd person's private key, the funds will be locked.
There's no workaround in MultiSig to spend the funds without satisfying the set condition of 3 signatures of 'N' number of cosigners.

and multi sig also require one seed phrase to import wallet? and how to make another wallet from multi sig to 2 person sig?

AFAIK, there's no single wallet software that does that.
It's unsafe to use a single seed phrase to derive the three keys since it'll defeat the purpose of the setup.
Each cosigners have to create their own cosigner wallets, they just have to get the other two's master public keys.
There's a workaround to that though: The Cosigners can set their own unique strong "BIP39 Passphrase" of a single seed phrase to make their cosigner wallets.

The steps to setup the wallets differs per wallet software, so what software is it?

[Don Pedro Dinero]

Since it's 3-of-n MultiSig, without the 3rd person's private key, the funds will be locked.

I don't see the point of having a multisig of 3, where all three signatures are needed. Better a 2-of-3.

Are you just asking hypothetically, OP?

At the individual level a 2-of-3 already provides a lot of security, I don't know if for very high net worth individuals or at the corporate level it would make sense to have more.

[cafter]

Are you just asking hypothetically, OP?

yes, for learning purposes,

[mk4]

What Charles-Tim said. In the first place, you should arrange/plan the multi sig with the assumption that one or a few people in the multisig might die or becomes disabled to the point that he/she wouldn't be able to sign a transaction.

You should almost never be doing X of X multisig, but instead X-n of X, as some sort of insurance for potential unfortunate circumstances.

[dzungmobile]

Multisig wallets

• Creating a multisig wallet
• Multisig wallets

Two Factor Authentication wallets

• Two Factor Authentication
• How to recover access to the bitcoins in your 2fa wallet

I hope you get some points and meanings from above guides to understand more about Multisig wallets. Such wallets are designed to be helpful for preventing loss of your bitcoins from a single wallet hack. To successfully hack and get access to bitcoins stored in a multisign wallet, a hacker must hack enough co-signer wallets to sign a transaction to move your bitcoins to a hacker wallet.

A more co-signers required for that multisig wallet, a more difficult for hackers to succeed.

One more helpful use case of such wallets is to prevent bitcoin loss because of one person death. If you use a single signature wallet to store your bitcoins, and you die, nobody can access your bitcoins if you don't let anybody knows about its private key.

[Woodie]

Multisig wallets

• Creating a multisig wallet
• Multisig wallets

Two Factor Authentication wallets

• Two Factor Authentication
• How to recover access to the bitcoins in your 2fa wallet

I hope you get some points and meanings from above guides to understand more about Multisig wallets. Such wallets are designed to be helpful for preventing loss of your bitcoins from a single wallet hack. To successfully hack and get access to bitcoins stored in a multisign wallet, a hacker must hack enough co-signer wallets to sign a transaction to move your bitcoins to a hacker wallet.

A more co-signers required for that multisig wallet, a more difficult for hackers to succeed.

One more helpful use case of such wallets is to prevent bitcoin loss because of one person death. If you use a single signature wallet to store your bitcoins, and you die, nobody can access your bitcoins if you don't let anybody knows about its private key.

Thanks for the extra information, but you have anchored this topic to a wallet being hijacked by a hacker but clearly OP was asking if there was a workaround if a co signer passed in a case of a 2 of 3 or 3 of 3 and  @Charles-Tim and @nc50lc have given suffecient answers to the question

[Charles-Tim]

Multisig wallets

• Creating a multisig wallet
• Multisig wallets

Two Factor Authentication wallets

• Two Factor Authentication
• How to recover access to the bitcoins in your 2fa wallet

I hope you get some points and meanings from above guides to understand more about Multisig wallets.

2FA wallet is different from multisig wallet.

Example of the 2FA wallet is the Electrum 2FA wallet which your referred to, it is true that it is 2-of-3 multisig wallet but how it is created is very different because 1 keys is known by Trustedcoin server which is used to sign a transaction whenever you are broadcasting a transaction that you signed, the second signing is from Trustdice server. You can be able to disable or bypass Trustedcoin signing or keys in which you can use your other key which is the second one with you to sign a transaction as two keys are needed. No second person as a business or family with you not to talk of the third person which the OP is referring to.

Because Electrum 2FA (or even lightning network) have multisig setup functionality does not mean we should refer to them as a multisig wallet.

[Z390]

It can never be me, there was a story like this with the bank in my city where three men have to sign before withdrawing their money and one was dead, this caused a big issue and they almost lost the money to the bank, until they can prove to the bank that the third person was really dead. Now we are talking about Bitcoin, it is gone forever if one of the 3 is dead, there is no making this right than to give up. This type of plan should be carefully think about before proceeding, ask questions about what will happen if one of us is down, have a backup plan just in case.