You start on a 5 x 7 grid with 5 letters and 5 adjacent letters available, and your opponent has the same set up on his side of the 7. You conquer territory by using letters that you can see, which are all letters adjacent to your current holdings. Each letter can be only used once and "your" side of the board is generated based on your current ranking (people who have a low ranking get generated letters like A R E S T, people who have a high ranking get generated letters like Y V Z X W, etc.). Usually, two competent players meet at the midpoint of the board after having conquered ~3 rows each to meet at the middle row. When a person plays a word using neutral letters in the middle, they become his. When an opponent plays a word using your letters, they become neutral. So, for example, let's say the board looks like this:
A R E S T <- Opponent starting block
H T U C P <- Opponent second row
L I E M D <- Opponent third row
Y J E L K <- Center row
P O C Q I <- Your third row
R E S L N <- Your second row
K U R M E <- Your starting block
Let's say your opponent went first, so they reach the middle row and they make J E R K Y. This allows them to control the Y J E _ K letters, while L remains neutral. In your turn, you don't have much opportunity to use all of the letters that your opponent used, since Y J E K is a difficult combination to implement. So, instead you may do J E L L Y which makes you neutralize Y J E _ _, take ownership of _ _ _ L _, and _ _ _ _ K remains in their possession. Thus, you are able to "scout" that adjacent to that L, they have E M D in their 3rd row. However, because they made J E R K Y first, they can see that your third row is P O C Q I, and because they retain control of the K, they can in their next turn neutralize your Q I in your third row. So, in their next turn, they would optimally want to neutralize the letters you own in the center and in your third row that they have contact with (L in the center, Q I in your third) and take back the letters that you neutralize (Y J E in the center). However, this is again very difficult to do because Y J E L Q I is practically impossible to string into one word. So, you have to prioritize what you want to do. In this case, the enemy could neutralize L Q I so that they create a buffer zone between their K holding and your available pieces, making it effectively safe for at least a single turn. Or, they could try to reclaim Y J E and neutralize L to reset the center of the stage in their favor. That's where the intricacy of the game comes in.
If I was your opponent in this case, I would probably play Q U I C K L Y in order to regain ownership of the center Y, neutralize your L, and neutralize your Q I. Now, you not longer have an avenue to attack my K and you lose your L holdings in the center row, thus giving me advantage.
This is a very simple walkthrough of the basics but there were other complications involved such as how to handle impassable blocks, using push tactics, the fact that your turns are timed and that there is a buffer timer to play with, etc.
Basically it was one of the greatest games I ever played but it never really took off and the devs were too lazy to make a mobile version and thus it died some 5 years ago.
EDIT: Also, I should note that I may have single-handedly destroyed the game because I was so dominant that no one else had a chance. I lost a tournament only once I hit A rank (and won the remainder of the game devs' money which they promised to the first person to hit A, which they at that time needed to pay for server fees lol). Also I guess one time when the opponent admitted to cheating by using a Scrabble Solver. When I hit A rank and was facing C rank players, I was getting boards like
Y Y Y Z X <- Third row
A U U K Q <- Second row
E B Y Z Q <- Starting row
Shit was brutal.