All right. I'm here with Ravinder, and we are going to play our game now in Chrome with MetaMask. And as you can see, Ravinder is here in the video chat. Hi Ravinder. --Thomas. Hi there. Hi there. I guess, Ravinder, are you up for a little game? Little Three in a row Game?

I think so. Let's give it a try. Just to give you a heads up, having my MetaMask here on the Ropsten test network, and I've pretty populated as we've done it before in our lectures with some ether still have them. And I'm going to hit the 'Create a New Game' button, and MetaMask pop up comes up and tells me I have to transfer 0.1 ether to the game and that's going to sit there and escrow until we have a winner. And I can also follow this transaction here in MetaMask. When I open MetaMask, click on the 'Transaction' and then click this 'View on Etherscan' button, and this will open Etherscan; the block explorer, and tell me at which time my transaction was sent off, how much did it cost and so on and so forth. And also that it's pending. And as soon as it's going to be mined. then I get an address here which I can send over to Ravinder, who is having the same game opened, the same website opened, and he can join the game. Let's just have a look. It might take a while. One of the drawbacks of Blockchains, extremely secure but quite slow. All right. We could use a little bit of this elevator music. Yes, we're waiting for transactions to process. Yes. One interesting feature of MetaMask. Now the transaction is confirmed, and I can send this address over to Ravinder. I'm going to open the chat here. I can send you a new address, and you can just copy and paste it into the field.

To join the game. So, I'll get a MetaMask notification also pop up. So, just confirm. And then I should be joining the game any minute now. All Right. But we can also see if we copy the game address. You can search for it on the scan and we can see what kind of transactions are happening. So, we already created the game. And then there is a new transaction from Ravinder. But I can see his address here which is 0.1 ethers are coming in, but it's still pending. And as soon as the transaction is confirmed, we should see our game field here with the 3x3 table where we can click around. All right, now it's my turn. And I guess, for you Ravinder, it says waiting for opponent.

For me, it is waiting for opponent right now. Okay, now let me click in the left top corner, MetaMask opens this time. We don't transfer an ether because we have already ether escrow and that just hit the 'confirm' button. And now, we have a waiting game again.

Here we are. So, now. I've seen it pop up now, so I put your mark. For now it says, "Your turn." So, I'll go with bottom right. So, once again MetaMask is popping up again for me. Then I click 'Confirm' and it should now switch back any moment.

All right, let me check on Etherscan. In the meantime, we see our transactions are ongoing. Yours is still pending from one second ago. And as soon as that's confirmed, then we should see it over here. Also good to know as a reminder on the theory, you have a block mining time of anywhere between 10 and 20 seconds. Mostly on average between 14 and 15 seconds. And that comes from the amount of hashing power that's available on the network. If mining takes longer than 20 seconds, difficulty will go down. And if it's less than 10 seconds, difficulty will go up. All right, I can see your stone. Here now on my game board, and I'm going to play something in the sentinel.

Let's check if the transaction, is Etherscan, we can see it here. Again three seconds ago. And I mean maybe for three in a row, a quick game, it is not the right platform. A Blockchain because it takes so long. Maybe something like a layer two solution on top of it would be better where you have a little bit less security but much faster transaction speeds. But if you think of something like larger financial transactions like the bond auction from the Austrian government where you need this level of security than the lower transaction speed. Might not be an issue compared to the cost that you save when you use traditional databases. Anyway. Do you see my stone popping up in the center? I do. Yes, I've got your stone right there. So, it is my turn. So, let's go ahead now, and I have now placed my new position.

Okay. There seem to be an interesting thing on the Ropsten test that were going on here. It says my transaction was reverted. But... Might be an error.

Okay, so I've had something pop up on my side which is a transaction failed. All right. At this point we would probably have to restart our game because our app doesn't yet take care of any errors that are happening. It just for now takes the absolute but it assumes that transaction will go through and we don't take care of any side effects. Like some transactions are reverted for whatever case, or you're hitting the Reject button. What are we gonna do now? Should we restart again? Or.. Let's restart again. All right. Just, I going to reopen the page here. Create New Game. Confirm. Let me check why this transaction... We don't know why this transaction didn't go through. And that is also the reason why it's so absolutely important to always test your distributed applications. Developer network and then on the Real Blockchain before it deployed to a Live Blockchain. Let me just send you the new address.

Okay. All right. Because of the Developer Blockchain, you usually have zero to no problems. And as soon as you go to real Blockchain, like the Ropsten test network, there you find difficulties where the mining time takes too long or if other influences before you deploy it to a main network where everything that costs real money. Right. Now it's your turn, I believe? Here we are for my turn. So, we stick with the bottom right again. All right. And that should be switching over to you any minute. There we are. So, that transaction confirmed. Yep, I got it. Now let me set the stone in the center. And for my next transactions, I guess I will increase the gas amount that I provide, all the gas fee, so it will mine faster.

Here we are. So yeah, I'll switch back. Pretty quicker chain. So yeah, if I work here, if I speed up the gas, put more gas in for that transaction, and submit my position. All right. Okay. Place it here on the top. And then make a fast transaction. Let's see what happens here.

That's starts come back. My turn, if increase the gas fee, which is pretty slow right now, but it's not too fast. And 'Confirm'. That should come through now any minute. There we are. Oh no. Ether place my stone in the wrong position. I didn't even pay attention. You're paying too much attention to the Blockchain. Oh yeah, that is definitely one of my flaws. I'm too technical. You won. Congratulations. Well, you guys.

I can collect your money, so now. Yes, you can. All right. Thanks so much to you, Ravinder. Thanks to you there for listening in, for watching the game. And I think we're done with our project. You can see, you can play Three in a row Game on the Blockchain now. And I'll see you in one of the next courses.

Playing the Game with Ravinder

About