Easy, don’t use grid squares, use zones.
This meme brought to you by theater of the mind gang.
This works for situations where exact positioning isn’t too important. When want to have AoE spells, move speed, flanking, and battlefield control, it generally because difficult to ensure that the GM and the players have the same picture of the battlefield. Even just drawing it out roughly can help a lot, but pure theatre of the mind really works best when you only care about distance rather than relative positioning and complex battlefield conditions.
I would love to play theatre of the mind, but my table collectively has the spatial awareness of a barnacle.
This brings us back to zones, a good middle ground. Draw rough map, or great map, and on it mark intresting combat zones. Some are separated with emptiness, others by obstacles.
For example a tavern brawl. Zones could be the Bar, Kitchen, Common Room, Balconies, Private Rooms, Out Front and Out Back.
Fighting on the Balconies could be tight, only one in width and with the risk of being thrown off it into the Commonroom. In the Kitchen there would be fire hazards, improvized weapons, knifes and the Stew. Not to forget other ways to spice things up in there. Around the Bar there would be some cover fighting someone on the other side, bottles to be broken and combatants to glide alond the bar for maximum mental damage.
And so on. Make each zone memorable and with special features. Did I mention drawing it out really helps?
Just drawing the situation out, even roughly, is already an enormous step forwards from theatre of the mind, and is doing most of the heavy lifting here. It’s also not “theatre of the mind,” like the original poster is implying. It’s a map, just one without grid-spaces or precise distances.
