Older RPG's were very linear, you have to do A before you do B to then do C. Testing that kind of game is very easy.I thought about arguing several points made in this post, but it really didn't contribute anything to the thread or tenor of discussion, so why bother? Therefore, I only want to correct this single error, rather than argue opinions.
Anywhere along the timeline of PC-based games, from the early 1980s onwards, both linear and nonlinear RPGs were popular. In fact, the most popular series were nonlinear: Wizardry, Ultima, the Magic Candle, and Might and Magic. They fit the classic profile of "do anything, go anywhere." There were other RPGs that were linear, such as the SSI "gold box" series, but these appeared a decade later; and there were still many nonlinear RPGs being released at that time, such as Bethesda Softworks' Elder Scrolls: Arena, and Microprose's ground-breaking Darklands. Even the first chapter-based RPG, Betrayal at Krondor, allowed you to roam freely in each chapter--within a series of boundaries, it's true, but that boundaries were huge, and dictated by the game plot. There were numerous optional subquests, and entire routes you could try or ignore.
Ah, good times, then--and now.
