The essence of the Tri-Level Resource Exchange Model is that you take resources, convert them to intermediate resources, and then convert those intermediate resources into resources that actually feed into the winning condition. So, here I have a diagram of the "Alpha Node" or point of choice where the players choose how they want to go about using their Level 1 resources to acquire Level 2 resources:
After the Alpha Node point of choice, the players then have to decide how they want to convert their Level 2 Resources into Level 3 resources, thus creating a second point of choice or Beta Node:
Now, from the decisions in the Beta Node regarding how to use one's Level 2 resources, come one of three possible types of Level 3 resources:
The VP resources feed into the winning condition:
The "dynamic" Level 3 resources actively feed back into the system:
The feedback loops are of one of three possible types and one of two possible sub-types:
External Game Generated types include situations where the game actively influences what a player can do based on that player's Level 3 resources.
External Player Generated types are where one's Level 3 resources in some way interact with or prevent what other players can directly do to you at the choice points.
Internal Player Generated types are where you simply help yourself in some way that doesn't involve a decision by other players or a "conditional decision" by the game.
Some examples will help illustrate my points:
-A perfect example of an external game generated feedback loop would be the changing of turn order in Power Grid. It is a direct influence from the game exerted on the players based on the amount of Level 3 resources they have.
-An example of an external player generated influence would be situations where you obtained cards or some other sorts of protections or mitigations from the direct attacks of other players.
-An example of an internal player generated influence would by like the "Hacienda" in Puerto Rico. It gives the player a chance to make a choice that can influence one of the interactions in the game - but the player doesn't have to do so.
The two sub-types are either Conditional or Random. With the Hacienda, it is an internal player generated influence but it's subject to randomness. With turn order in Power Grid, it is a game generated influence that is strictly conditional based on a set of criteria.
So, the Alpha and Beta Nodes are not only decision points where player choice is introduced into the system, but they are also points of entry for influences:
So, now that the context of the model has been established, two more assertions I have about what makes for "good" game design will make sense:
-Postive feed back loops for players should be counter-balanced in some way by some other aspect lest a run-away leader problem emerge.
-In situations where External Player Generated influences result in direct loss of resources by one player, having more than two players presents a situation where the game can suffer from triangulation problems (I've written previous posts on this concept).
Edit: One more thing to include with this model before moving on is that Internal Player Generated Feedback influences don't always simply influence the choice nodes. Sometimes the manifestation of this type of feedback influence...
...is the fact that a Level 3 resource doubles as a Level 1 Resource:
Examples of this include how Settlements in Settlers of Catan, Buildings in Puerto Rico, and Buildings in Caylus are the results of Beta Node choices regarding Level 2 resources but they also serve as Level 1 resources in helping create Level 2 resources.
*In part 3, I'll discuss a second model of design called the "Tri-Stage Resource Transition Model". It's a model that is decidedly different from the Tri-Level Exchange model in its form.