Idea Time With Telamon


We have monthly troupes of kid visitors at ROBLOX HQ (more than monthly in the summer), and when they come I always like to gather user feedback in the form of a game.

“Let’s pretend that you are Builderman and you run ROBLOX. You’ve got a limited number of programmers. What features do you want to add to the game?”

I played this game with some users yesterday – the above picture is the resulting whiteboard.

Everyone throws ideas up on to the whiteboard for about 15-20 minutes. Then everyone gets three votes. There’s a lot of debate between users stumping for their favorites. The top 3-4 ideas go into my mental catalog of things that we should really get around to doing at some point or another.

Usually winning ideas are things we know we need – but sometimes something that we thought was less important bubbles to the top unexpectedly.

In this particular case a terrain-building tool was the surprise winner. I was chatting with some members of the engineering team today about we could render expansive, editable, block-like terrain. If it’s been done in Java, we could certainly do something reasonably fast in C++.

Designing the ROBLOX Trading System

A lot of the backend work to support player to player item trading on ROBLOX is done. We’re trying to settle on a good front-end user interface. The feature we are trying to support is allowing Player 1 to trade items A, B, and C to Player 2 for items E and F – basically trade one “basket” of items for another “basket”. There are lots of usability considerations. Which of the following designs seems most useful to you?

Option A – “Real Time Face-to-Face Trading”

This is the trading system that almost all MMOs have used since the dawn of time (above screenshot is from Diablo II). Basically a trade works like this:

  1. Send a trade request to a specific player, who must currently be online.
  2. Player accepts trade request
  3. Both players are brought to a trade screen. It’s basically a table. You drag stuff from your inventory on to your side of the table. The person you are trading with does the same.
  4. Once the trade is acceptable to both parties, they click “Ok” a couple of times and the trade is completed.


  • Once you find someone to trade with, the trade happens pretty quickly
  • Easy to understand
  • The personal touch is fun. You can wheel and deal. Offers and counter offers are fast.


  • You can only trade with players who are online
  • You have to find someone “good” to trade with – they have to want what you have and have what you want. If you are looking for rare items, this can be very difficult.

Option B – “Bulletin Board Trading Post”


In this system, players post offers that they would be willing to do to a giant list of currently offered trades. People browsing the current offers can click to accept the offer at any time.

The screenshot is of Google Jan 11 Call Options on Yahoo Finance; maybe not the best example.

Basically, if I am interested in trading away my Domino Crown, I might post several trades:

  • Domino Crown for Eerie Pumpkin Head
  • Domino Crown for Crimson Catseye and Sparkletime Fedora
  • Domino Crown and Got Milk Visor for Red Domino Crown and Sparkletime Fedora and Helm of the Secret Fire

These would go into a giant list of all the trades everyone on the site is willing to do. If someone has offered the opposite trade, like “Eerie Pumpkin Head for Domino Crown”, then the trade happens immediately. Most often, though, the trade will go into a giant list. People can search through that list based on either what they are looking for or what they have to trade. At any time, a person can accept one of the offers and the trade happens instantly. If you want to wheel and deal, you do so ahead of time via private messages or on the forums.


  • You can trade with people who aren’t online. Other people can trade with you when you are not online. This means more potential trading partners.
  • Easy to find people offering rare items.
  • Common trades (between like-valued objects) can be executed instantly, since you don’t even need to talk to another person.
  • Offers are public, so everyone has a good idea of what different items are worth.


  • Complicated trades involving many items are hard to find matches for. Ex: A, B, C, D, and F for X, Y, Z, and Q.
  • All trades are public – you don’t specify who on the other end you trade with.
  • Harder to wheel and deal

Option C – “Send Specific Offers Through Private Messages”


This is a lot like Option B except that there is no giant list of all trades. Everyone posts their want and have lists to a forum and you can send people trade offers via private message. They can either accept, in which case the trade happens immediately, or decline, in which case the trade obviously doesn’t happen. Perhaps there is capability to send a counteroffer or modification to the proposed trade if it is declined.

The screenshot above is from the Magic Online Trading League, which is an example of this sort of system in action.


  • You can trade with people who aren’t online.
  • You can trade with specific people.
  • Pretty simple to understand.
  • Wheeling and dealing happens in a public forum, so it’s probably harder to get ripped off because someone will tell you a trade is bad.


  • Takes a lot of “leg work” to find a good trading partner.
  • Trading can be slow – by the time you hunt down someone who has the item you want, they may have traded it away already. It might take you 1-3 days to find out he doesn’t even have what you want any more.
  • Have/Want lists posted to a forum doesn’t seem like a very advanced system. Forums were not built with the idea of trading in mind, and Option C makes a forum “the spot” where all the trading action happens. A dedicated interface would offer better affordances.

Option D – “Real Time Auction House Best Offer”

There is a special “Auction House” page on There’s a chatroom with a ton of people in it. There is one trade going on at a time. This is how it works:

  1. If you want to sell something, you wait in line, since only one person can be selling at a time.
  2. When it is your turn, you put together a “basket” of items.
  3. Everyone else in the chatroom gets a chance to construct an offer “basket” – things they will give you for your collection.
  4. As the seller, you pick which offer is currently winning. This is the “best deal” you have been offered for your set of items.
  5. Everyone else has the chance to top the best offer.
  6. After 2-5 minutes of this, the auction ends. The current “best offer” wins and the buyer and seller exchange baskets.
  7. A new auction starts.


  • A real time auction would be exciting for rare items or expensive sets of items.
  • The buyer gets the best possible deal anyone present is willing to offer. So it’s hard to get ripped off.
  • The results of the auction are public, so everyone has a good idea of what different items are worth.
  • This is a super easy way to unload 50 worthless items at the same time and get back something good in return.


  • A real time auction would be boring for common items or cheap sets of items.
  • You can only trade with people who are: 1) online and 2) present in the auction house. This probably makes it harder to get the best possible price for a rare item that may not have many potential buyers.
  • When you want to trade, you want to trade. You don’t want to stand in line to sell items.
  • If there aren’t enough buyers logged into the auction house, the whole system stops working.

Vote on which trading system you think would be the most fun to use.

The Apotheosis of Man–Or His End

There is something incredibly creepy about watching a supercomputer beat the best human players at Jeopardy. For neophytes: writing a computer program that plays Jeopardy is a super hard problem, and this is nothing less than totally amazing. The hardware specs on Watson are crazy – 2000 cores and 15 terabytes of RAM. I think all the hardware is general purpose (Deep Blue had purpose-designed chess-accelerator chips).

I wrote a research paper on Deep Blue in college – in the aftermath of it trounching Gary Kasparov, IBM’s stock shot up 10%, so I’m loading up. Sure, the human race might be doomed, but that’s no reason not to make a quick buck.


Engadget puts annoying commercials in these – what can I do?