Tactical scale is the most zoomed in. It can be dealing with units as small as squads or even single soldiers. If it uses a hex mapboard, the hexes may represent 20-100 metres across. And the time scale is often variable, but generally short. A turn might be 30 seconds, it might be 5 minutes.
The size of units can be bigger. There are platoon or company size units in these sorts of games as well. Think of games like Combat Commander or ASL, and then up to MMP’s The Greatest Day series. (MMP calls these games Grand Tactical, but it’s not a universally recognized distinction.)
One way to easily know if a game is tactical right away is if there is any ranged firing or LOS rules. If you can only hit a unit in the next hex, it’s probably not a tactical game. If you can hit a unit a few hexes away depending on line of sight, it’s going to be tactical.
In between tactical and operational games is a group that I sometimes call “battle games”. These can have a bit larger unit, maybe battalions or regiments. Infantry generally can only fire into an adjacent hex or maybe one extra, but artillery can still fire at range. There’s still a fair bit of maneuver available for the faster units. Turns might be 30-60 minutes. There are hundreds of ACW battle games at this scale, as well as Napoleonic games.
