From OHRRPGCE-Wiki

plotscr.hsd contains the definitions of all the standard plotscripting commands. Whenever you write a script, you should put the following line at the beginning:

 include, plotscr.hsd

If you forget this line, you can expect to see errors like:

• Unrecognised name _____. It has not been defined as script, constant, variable, or anything else
• Expected number but found _____

[edit] See Also

• ERROR: File plotscr.hsd not found. What should I do?