Soak is defense bought just to die and not to absorb.
Resource abbreviations: E means energy, G green, B blue, R red, and X means attack. Gold is denoted just by a number. So for example, we would say that Centurion costs 18GGBBR.
p1 and p2 refer to the players who go first and second.
BSO = Base set only.
Base + x means the set of units including the base set and the listed units (or the listed number of random units), eg. Base + Borehole Patroller, Base + 5.
The base set units are commonly referred to by the first letter of their name, eg. "T is more efficient than S". Note that some of these conflict with the resource abbreviations.
To refer to turn numbers, t4 is turn 4, etc.
Line notation: Although many openings have names (see my opening list), people often still refer to them by specifying every move. So for example, to open DD/DA as player 2 is to buy 2xDrone, then Drone+Animus (this is the common opening 'Fastimus'). We can also use turn numbers to jump into the middle of a game, like: "p1 should play 6: WEB there".
autowin: one player (p1 or p2) always has an unbeatable line. An autowin is is a set where the winning player's obvious moves are good enough to beat near-perfect play by the losing player.
A legendary unit is a unit that has only 1 supply.