Valve products have always been especially kind to deaf gamers. Dota 2 has always let you ping and draw on the mini map, but they went one better when they added the chat wheel, which supports a large range of subtitled tactical “shouts”, including the ability to add your own custom ones. This feature effectively negates both disability and language barriers.
Justin Cheadle, gamer & developer, deaf
Either environmental, allowing points on the map to be pinged for other players or markers left directly in the game environment, or directly, via player emotes.
Particularly useful for players with impaired speech, or hearing, but also a useful tool for all players regardless of impairment.
Best practice example: Dawn of war II