A gaming chair is the one piece of your setup you touch for every single hour you play. Getting it wrong means back ache, numb legs and a chair you quietly stop using.
Measure the space you have and your own hip width. A seat that is too wide stops the side bolsters from supporting you at all; too narrow and it digs in. Most adults are comfortable in a 50-55cm seat pan.
Thick foam feels great in a showroom and flattens within months. Adjustable lumbar support - either a pillow you can reposition or a built-in mechanism - is what keeps your lower back neutral through a six hour session.
A 90-135 degree recline covers upright play and leaning back between matches. For armrests, 2D (height and rotation) is the practical minimum if you switch between mouse and controller.
A five-star aluminium or reinforced nylon base with a Class 3 or 4 gas lift is the difference between a chair that lasts years and one that sags. Ask about the gas lift rating before you buy.