Gaming PCs pack the heaviest and most expensive components of any computer, from massive graphics cards to bulky air coolers and liquid loops. Those heavy parts hang off the motherboard and sag or stress their mounts when the case is bumped or tilted. Bracing the vulnerable pieces is the key to a safe move for a high-end rig.
Pro tip: Photograph your cable management before disassembly so reassembly is quick.
Watch out: A heavy GPU left installed can crack its PCIe slot during a move. Remove it or brace it firmly.