Roger Firth's IF pages
InfAct -- about Inform NPCs

Like its associate InfLight and InFancy, InfAct is an Inform overview site, this time covering Non-Player Characters (NPCs). As before, this is just a sampler of the tools and techniques available, more a kit of parts than a ready-to-run solution; the work of breathing life into your creation is a long hard slog, but very rewarding if you make a success of it.

The material is loosely organised as follows:

Basics

What makes an NPC? And what makes him come alive?

Silent interaction

There's always room for a little give and take.

Conversation

"Hello, Sailor" (or, more accurately, "Say good morning to the ancient mariner").

Conversation packages

Some assistance in keeping things moving in the right direction.

Orders

Sometimes, you've just got to tell 'em what to do.

Movement

Cut the ties that bind! Set them free!

Conventions

To clarify where the various example displays come from, a little colour-coding is used:

This is a sample of text in an Inform source file.

This is from a Z-machine interpreter at run-time. 

Acknowledgements

Various modules are mentioned along the way; my gratitude, as ever, to the authors concerned:

• Start at the Inform home page for details of the environment in which we're operating.
• Be sure to read Emily Short's fine essay on NPC characterization.
• Pick up Irene Callaci's AskTellOrder.h, L Ross Raszewski's Converse.h, Adam Cadre's Flags.h, Jesse Burneko's Info.h, Neil Brown and Alan Trewartha's MoveClass.h, Adam Cadre and David Glasser's PhTalkOO.h, Volker Lanz's NPC_Engine.zip and David Cornelson's WhoWhat.h from the archives at if-archive/infocom/compilers/inform6/library/contributions.
• You can get the Cloak of Darkness example game from this site.

We'll begin by creating a minimal NPC object, then provoking a few reactions.

Intro Basics Silent interaction Conversation Conversation packages Orders Movement