There are two ways to get into designer mode; one is to start up a game
with the appropriate option (-design
under Unix), which makes
every player with a display a designer, the other is to switch on a flag
after the game has started. Being a designer is a property of a side,
so in theory a game could have a designer and several other human
players, or even multiple designers (this might be useful in having
assistants to help with the construction of large scenarios, or just to
have displays open to each side's view of the scenario). AIs
effectively sit out the game while designers are present.
Designer mode enables an additional set of commands on the menu or map control panel, as well as removing some restrictions on the use of normal commands. It also enables more elaborate game saving machinery, so you can save only the parts of a game that you want to make into a scenario.
Modifications to normal commands include the permission to look at and do any command on any unit, including independents and units belonging to other sides. For instance, any unit can be renamed at any time by any designer in the game. The modications include the following:
Some interfaces may also provide additional tool palettes and the like.