# Part II: TADS 3 In Depth

This section looks at important TADS 3 programming topics in detail. Most authors working with TADS will encounter these topics at one point or another.

Where Messages Come From
Action Results
Verify, Check, and When to Use Which
How to Create Verbs
Custom Preconditions
Message Parameter Substitutions
Implied Action Reports
Lists and Listers
Tips: A Context-Sensitive Help System
Creating Dynamic Characters
NPC Travel
Using the Banner API

TADS 3 Technical Manual
Table of Contents | TADS 3 In Depth
Prev: Bibliographic Metadata - the GameInfo Format Next: Where Messages Come From