I've been encountering a problem in some of my more complicated programs. 

The problem is best illustrated with an example.

Example:
 Suppose you are playing a multiplayer team FirstPersonShooter. 
 You need to send messages to other teammates like: 
  * "Follow me to the <waypoint2>" or
  * "Get in the <vehicle1> and I'll get in the <vehicle2> and give you cover while we go to the <waypoint4>" or
  * "I'll remain in the <base> while you go attack the <target> with the <vehicle>"
(''<stuff> denote things that may have different names in different games.'')

Problem: What system would be expressive enough to send messages of that nature to other teammates - in a couple seconds, with only a few keystrokes? Time is an extremely limiting factor here as there is not time to actually type such a message. Keystrokes/keyboard bindings are a factor too, as many keys are already bound, and the player won't wish to move their hands off the movement keys.

''Speech. Which is typically how games today seem to solve it.''

Erm. . . yes to a point, except most modern VoiceOverIp is extremely lacking. . . it also doesn't work with bots. The problem is also prevalent in many real-time musical systems, something speech wouldn't help with.

''Voice recognition, then? The point being your primary interface (the keyboard) is already too fully utilised to use for this. Anyway, how cool would it be to say "Hal, tell Dave to follow me"!''

Yeah, I hate to do the moving goalposts thing, but the speech/voice approach just isn't going to work for musical systems(especially at shows with loud speakers). I didn't mean to say the keyboard was too overloaded to be usable, just that it would have to be something fast. Like assigning tokens to shift-<number> so you could rapidly type out "common words", sort of how courtroom typists use keyboards with syllables instead of letters. I suppose a radial menu could do something similar to this. . . 

''The Tribes games have a system somewhat like this. A player can press "V" at any time to open the voice menu, and then they can navigate through a tree of options by pressing the appropriate keys. The problem of too many keys being taken up is solved by the fact that only one key is needed to activate this command, and then almost every key near where the hand usually rests changes functionality to navigate the tree. All of the dialogue options take either three or four keystrokes, and take less than a second to input, once the player has the tree memorized. It doesn't have quite the detail of the examples above, though. "Attack the enemy base with a mortar!", "Repair my vehicle!", or "I have the enemy flag." are about as complex as it gets. Also, the tree cannot be extended by users. It's a fairly good system.''