Every so often, we ask a series of MMO developers to answer a single question about game design and / or design theory. This week, we ask about the sandbox design model and why it has remained popular.

Sandbox games have proven that they stand the test of time. Why do you think the sandbox model appeals to players even after all these years?

Sandbox games lend themselves very well to the traditional MMO business model. The MMO monthly fee business model relies on players not only purchasing the game but continuing to play it for years. The basic idea behind sandbox games is to provide players with a virtual world (one that is more exciting than the real world) and the tools to enjoy living in that world. There are many aspects of these games that keep players paying, but three core concepts immediately come to mind.

Ownership

An important aspect of sandbox type games is that players can actually own a piece of the game world. In Ultima Online, the areas where players can place houses are spread throughout the actual game world instead of instanced or placed in special zones. Houses closer to moongates or in other high traffic areas are worth a fortune to merchants. There are also factions the player can join that have the ability to take over cities in the Player vs. Player lands. By allowing the player to own a piece of land, it gives the player a home and makes them feel personally invested in the world.

Persistent World

Our server doesn't just save out player character data. It stores the location and properties of every object in the world. Most items decay after a period of time, however players can lock items down in their house to avoid this. Players spend hours decorating and redecorating their home with rare items which are both crafted and found throughout the world of Sosaria. I've seen some truly unique and amazing custom player houses during my time on UO.

Over the years different event moderators and GMs have placed items that can only be found on a specific shard. The Atlantic Mage Tower is a good example. It was created by a GM years ago and only existed on the Atlantic shard. Unfortunately, the original Atlantic Mage Tower is no longer standing. However, a player has since placed a house in its former location and tried to recreate it to the best of his ability.

Open Ended Character Development

In Ultima Online, we provide open ended character development through the skills system. This gives our players more freedom to build their character's to suit their specific play style. In a level based game, character development often stops when a character reaches max level. In Ultima Online, players are constantly tweaking their build and adding new skills to their repertoire. We have objects in the game called soulstones that allow players to store off skills, leaving room in their template to train new skills.

When these concepts come together, they create a truly immersive experience. Our players feel they are living in a virtual world instead of just playing a game. While newer MMOs have become increasingly linear in both character development and overall game flow, sandbox games like Ultima Online remain open ended and provide players with an unparalleled sense of freedom. This is why we have players that have been paying for their subscription for over 12 years.

Check out Monday's response from Fallen Earth's Wes Platt, here.

Tuesday's answer came from Nathan Richardson of EVE Online here.

Wednesday's answer came from Earthrise's Atanas Atanasov here.