SWmud

This command *adds* speed to your ship's current speed. If you want to slow down, you add *negative* speed: <speed -100>.

You can also provide an option second argument for autopilot ticks. This will make your ship stop automatically after that many movement ticks. So multiplying your speed (after your acceleration) by your autopilot ticks tells you how far you will go before your ship automatically stops. It is advisable to keep that number lower than the distance between your ship and whatever it is facing.