Game Development Reference
Figure 13.18 Final Black Pendant test tree design structure, Part 2.
One final caution. Be careful about trying to reuse test trees for sequels to previous
titles. In the collectible card game example, the tree may not be complete for Yu-Gi-Oh!
titles released after Eternal Duelist Soul . This is because new card mechanics, card
types, card restrictions, and/or rule changes can be introduced as new cards are
released to the public and included in subsequent videogames. Go back to the point
prior to fitting specific cards to each branch and use that as your starting point for
completing your test tree designs for newer titles.
This design technique is also useful to fill in the “whitespace�? of any feature where you
already have experience or intuition of what should be tested, but want to ensure
more complete testing, especially concerning various interaction or situational possi-
bilities. In addition to applying this technique to card battle games, you may also find
test tree designs useful for testing things like computer opponent AI, networked game
message processing, or spell interactions and combinations.
Tree structures are useful for organizing test cases so that the proper set of tests can
easily be selected for a given set of changes to the game code. Each downstream node
represents a set of tests with a more specific purpose and scope than the nodes above.