This discussion of the use of microcomputers to simulate complex situations for classroom use describes the advantages of using simulations, including their adaptability to many subject areas and content fields, their power to explain complex concepts, and their ability to provide variations for individual users. As an example, seven objectives that were important to social studies teachers before the advent of computers are identified, including strategies (new experiences, new sources of information), content (facts and concepts), skills (inquiry and social interaction), and attitude. It is pointed out that simulations can accomplish all of these objectives except the strategy of investigating new sources of information. It is suggested that teachers who wish to develop simulations for their students must select an appropriate event, which requires careful consideration of the relationships involved, the terminology to be used, the adaptability of the event for graphic or textual representation by a microcomputer, and the characteristics of the intended learners. A sample simulation program is briefly described, and an example is given of programming in BASIC which allows inputs while the program is operating and the graphics display is being generated. The BASIC commands for this routine are listed and explained. Teachers who wish to develop their own simulations are advised to consider these conditions, and the use of the BASIC programming technique is advocated as a means of developing a more varied, active simulation. Seven references are listed. (DJR)