In essence is it is simply the delay between starting to attain an asset and the asset coming into play. This may be as trivial as collecting points through various means, to setting a sequence of events in order that will generate the asset. Examples of the first would be collecting lego blocks in order to build a house, while the second would be going on various quests to find the Holy Grail/Golden Fleece. There is a period of time between initiating the goal of having said asset and getting it. During this period there is no advancement though there are factors that continue to pose a risk.
In the case of the lego blocks, stacking them and moving away to find more leaves the stack vulnerable to lego thieves while the second puts the questing characters in mortal danger while they are out adventuring.
The role of the game designer is to balance the risk against the value/perceived capability of the constructed asset. Risking character death for a 0.1% improvement is not going to happen, while players will throw character after character into the pit just to get a thousand-magnitude upgrade (anyone playing old Traveller RPG will be familiar with the concept used in character creation).
There are therefore a few fundamental features (beyond the actual asset) to consider when assigning Construction Risk:
Never underestimate player desire for something few others have. While the vast majority of people are not prepared to pay more for a virtual item than the same item in real life (including spectacles, cars and prostitutes), they may well be willing to expend a lot of in-game resources, more so than the asset’s capability compared with standard/common equivalents.
There is a point where a delay turns into a grind. There is a point where a grind becomes a turn-off. Determining these values is dictated by the pace of the game. Where plans can span years (such as in Phoenix: Beyond the Stellar Empire), research times of a year are not unreasonable. Such things would be utterly insane in an Xbox game.
This is where the object of the plan is to achieve a psychological victory (rather than simply getting an opponent’s assets). The target in which the ‘flag’ is to be planted need not be defined by the game mechanics; it can simply be a group of players deciding that this is the object of the plan. The anticipated degree of kudos and self-congratulating determines the amount of resources that will be expended to achieve it. A good sandbox game design should embrace this. There are various tactics such as ‘halls of fame’, medals and various other forms of ranking achievements.
While plant-the-flag mechanics are good at promoting activity within a game, they do have the potential to become repetitive. Where a game is a persistent universe, there is the possible option of adding an ever expanding story arc. This is more suited to games that are turn-based and have a speed of play closer to real-time. The ability to build and destroy within a sandbox can lead to situations occurring that, when combined with a story arc allow for unique situations. This not only allows for a group of players to achieve goals similar to plant-the-flag, but dictates that some events can never be repeated. The destruction of an alien homeworld, the exodus of an entire species and the founding of a religion that will over the course of years, change the entire galaxy. Shaping the entire game universe for years to come (such as described in the Fall of Tate) is a powerful incentive to spend resources.