A delivery truck that once hauled goods all over town might now sit idle because a new highway made it useless. A brand name bought for millions could lose its shine when a competitor takes over the market. In this chapter, we look at how accountants test whether assets are still worth what the books say—and what to do when they are not. We also explore a special option under international rules that lets companies revalue assets upward, something U.S. standards do not allow.