From time to time, a pwad comes along which, instead of simply leading from one map into the next, tells a story by way of text which pops up after a map is completed and informs the player of some important information. Or, in case a TITLEMAP is used, at the beginning of the game.
This text can be inserted into the map in various ways. But all involve the use of a hub structured pwad by defining it in the MAPINFO lump. See the Wiki for MAPINFO/Cluster definition. Notice the differences between Entertext and Exittext.
Whichever method you will eventually choose, I cannot stress enough to use correct formatting for both MAPINFO and the scripts in the SCRIPTS lumps.
The map is defined to belong to a certain cluster, for example cluster = 1 and that cluster is specified in a cluster 1 block in the MAPINFO lump, for example:
This is a bit different from the above in that the text is in a separate LANGUAGE lump.
To exert some control over what the text is to look like as to position, color, font, etc one can use scripted intermissions.
For intermission text in scripts it is not necessary to define a cluster. In this example, because the Exit_Normal special is used, the next map is specified in MAPINFO.
The difference to the Exit_Normal example above is that the next map is specified in the linedef action special Teleport_NewMap
To give the player any information as to gameplay or game setup before the game starts, one could use a TITLEMAP. A TITLEMAP is constructed like a regular map but is called TITLEMAP instead of ExMX or MAPx.
Then set up the script to present the information about the game in the SCRIPTS lump. This could be the storyline or any visual effects to set the mood for the game.
Just as an aside for those interested:
Another good example pwad which includes the intermission text in MAPINFO is ZPACK.pk3
TITLEMAPs can be visually quite stunning, see for example KDiZD and TUTNTv1.08 and also very complex, not easily reverse engineered. Complex because scripting is not just in one lump but spread over several entries.
While challenging, it is well worth to try and decipher what and how this was done.
Kappes Buur, Sept 29 2016