I don't believe but I need to confirm from smarter people on here

[Lontor]

I am quite confused about this, I need some insight.

I was discussing with my family member about going Multisig some hours ago and what he said made me wonder if it's true or not.
He said that multisig rules is built into Bitcoin address itself.

I accept that nobody can have access to Multisig wallet unless they get the 2 recovery seed out of 3 but my question is this.
Since he said that multisig rules are built into Bitcoin address doesn't that mean I can't setup Multisig wallet for multi-coins?

Is he right or he is wrong.

[BluebloodCXVI]

I am quite confused about this, I need some insight.

I was discussing with my family member about going Multisig some hours ago and what he said made me wonder if it's true or not.
He said that multisig rules is built into Bitcoin address itself.

I accept that nobody can have access to Multisig wallet unless they get the 2 recovery seed out of 3 but my question is this.
Since he said that multisig rules are built into Bitcoin address doesn't that mean I can't setup Multisig wallet for multi-coins?

Is he right or he is wrong.

No it doesn’t stop you from using multi-sig on other coins though, bitcoin does it with native scripts, Ethereum and similar chains do it with smart contracts like “Safe”, and other chains also have their own ways too, so you can definitely set up multisig for multiple coins.

Although, you just can’t use one single Bitcoin address to control everything because each chain has its own addresses and its own system.

[Charles-Tim]

I accept that nobody can have access to Multisig wallet unless they get the 2 recovery seed out of 3 but my question is this.

This is a 2-of-3 multisig wallet. It is worth knowing that you can generate more keys and more cosigners up to 15.

Since he said that multisig rules are built into Bitcoin address doesn't that mean I can't setup Multisig wallet for multi-coins?

Altcoins can have multisig, but I do not know if they can be for a a wallet that is supporting multiple coins. The scam in which a scammer will tell a stranger that he has USDT on Tron blockchain and need the help of another person to withdraw the coin, the scammer used a multisig wallet to make the scam possible.

Ethereum, solana and many other coins support multisig.

[Bitcoin-Forever]

I accept that nobody can have access to Multisig wallet unless they get the 2 recovery seed out of 3 but my question is this.
Since he said that multisig rules are built into Bitcoin address doesn't that mean I can't setup Multisig wallet for multi-coins?

Is he right or he is wrong.

It's all depends on the wallet you are considering to use for your multi sig, remember that wallet like electrum only support for bitcoin network and that means you can only have Bitcoin setup on it while you can also consider other networks or wallet that support their network like that of the ethereum from the example mid mention above and set up their multique as well.

[Lemonmate]

Your family member is only partly correct, and it is true that in Bitcoin, rules for multisig are defined in script but multisig is by no means Bitcoin only. On Ethereum, for example, there are multisig options (eg. Safe), although rather than being defined in script, it is more of a smart contract wallet situation. On Solana you will get other solutions again. So while not common everywhere, you CAN set up multisig for various blockchains.

Whether or not you can use the same signers depends on whether they are supported both by the software wallet and the signer(s). Not many pieces of software are going to support multisig for multiple coins, and you may very well find you need a wallet for each, eg. Sparrow for Bitcoin, Safe for Ethereum, etc.

And lastly, seeds are not everything in Bitcoin, especially with multisig. You need to save the descriptor or related xpubs as well as the seeds in order to recover it.