If I had to describe 3rd strike in one word that would be "freedom". The game gives players a plethora of options in any situation. This is by design and has been discussed by Shinichiro Obata [1]: the game is built around "unanswerables" - the idea of creating situations with no clear answers/solutions/resolutions. This is done in order to avoid gameplay based around preset knowledge of situations, and instead emphasizes RPS mechanics more than other games in the genre. But how is this achieved in the game and what are its consequences?
The key to achieving such freedom is the heavy reliance on universal mechanics. The parry is an obvious example of this, along with mechanics such as the throw protection after blockstun/wakeup, crouch teching (also the extra damage done to crouching opponents). With the existence of those few mechanics, the player has plenty of tools at their disposal, that are universal across characters. There are no situations where the pool of answers is severely limited. Additionally, while some options cover a broader range of actions, the game always has a way to reward guessing the exact action that the other player will take. Because of this, every single decision carries risk and nothing is truly safe. Blocking is still the "safest" option, but it can be opened up by overheads into confirms and command grabs for reasonable damage. If that is not in a character's toolkit, then the simple throw loop in the corner can force out a reaction other than blocking. All of this contributes to creating an extremely unpredictable playstyle. Habits and predictable play can be punished severely, resulting in a game that promotes more attentive play and non-rigid playstyles.
Let's take a look at a practical situation in which those tools come into play. Dudley is a character with a strong 50/50 of an overhead or a low hit confirms that could lead to yet another 50/50 each time it is successful. If it is blocked correctly it leads back to neutral. In most other fighting games, without considering reversals (which still exist in 3S), this would be a situation where Dudley can use his absurd okizeme to play in a highly beneficial position. However, since this is 3S the opponent can always go for the parry instead. If successful it would give the defender a very strong combo in retaliation and more pressure afterwards as well. This turns the 50/50 into a double-edged sword. Yet while parrying is strong it still has its own counters - throws, delayed meaties, normals into cancels. In turn these have their own counters. The key takeaway is that, starting from 2 options (and potentially a throw sometimes), that would be the most efficient in most other fighting games, we get to create a variety of new options both sides have to consider and can use viably.
It is important to mention that those tools also limit the theoretical knowledge needed to play the game. While there is knowledge that could benefit a player, any situation provides enough information by itself for its resolution (answer). While frame data has its usage, it takes a backseat to elements like the pushback and ways in which an attack can be parried (low/high or both). Both of those elements can be deduced from the visuals alone. Even if it is a player's turn/a player has priority/advantage, the threat of a parry can steal that turn. This can be used both to escape pressure situations from frame traps or to even further your own pressure - the parry is a tool that can be used both defensively and offensively. Character specific tools still have their play, but rather than limiting or completely substituting your universal options, they tend to instead give you completely new options and create new situations.
All of it leads to some of the most unpredictable matches that one can find in the genre, while also being reasonably easy to play. It does require knowledge of those universal mechanics, but while more specific knowledge is helpful, it is often not required.
[1] If you want to read it for yourself I recommend the SF3 an oral history feature from polygon, the topic in question is discussed in the final bit of the interview.
The key to achieving such freedom is the heavy reliance on universal mechanics. The parry is an obvious example of this, along with mechanics such as the throw protection after blockstun/wakeup, crouch teching (also the extra damage done to crouching opponents). With the existence of those few mechanics, the player has plenty of tools at their disposal, that are universal across characters. There are no situations where the pool of answers is severely limited. Additionally, while some options cover a broader range of actions, the game always has a way to reward guessing the exact action that the other player will take. Because of this, every single decision carries risk and nothing is truly safe. Blocking is still the "safest" option, but it can be opened up by overheads into confirms and command grabs for reasonable damage. If that is not in a character's toolkit, then the simple throw loop in the corner can force out a reaction other than blocking. All of this contributes to creating an extremely unpredictable playstyle. Habits and predictable play can be punished severely, resulting in a game that promotes more attentive play and non-rigid playstyles.
Let's take a look at a practical situation in which those tools come into play. Dudley is a character with a strong 50/50 of an overhead or a low hit confirms that could lead to yet another 50/50 each time it is successful. If it is blocked correctly it leads back to neutral. In most other fighting games, without considering reversals (which still exist in 3S), this would be a situation where Dudley can use his absurd okizeme to play in a highly beneficial position. However, since this is 3S the opponent can always go for the parry instead. If successful it would give the defender a very strong combo in retaliation and more pressure afterwards as well. This turns the 50/50 into a double-edged sword. Yet while parrying is strong it still has its own counters - throws, delayed meaties, normals into cancels. In turn these have their own counters. The key takeaway is that, starting from 2 options (and potentially a throw sometimes), that would be the most efficient in most other fighting games, we get to create a variety of new options both sides have to consider and can use viably.
It is important to mention that those tools also limit the theoretical knowledge needed to play the game. While there is knowledge that could benefit a player, any situation provides enough information by itself for its resolution (answer). While frame data has its usage, it takes a backseat to elements like the pushback and ways in which an attack can be parried (low/high or both). Both of those elements can be deduced from the visuals alone. Even if it is a player's turn/a player has priority/advantage, the threat of a parry can steal that turn. This can be used both to escape pressure situations from frame traps or to even further your own pressure - the parry is a tool that can be used both defensively and offensively. Character specific tools still have their play, but rather than limiting or completely substituting your universal options, they tend to instead give you completely new options and create new situations.
All of it leads to some of the most unpredictable matches that one can find in the genre, while also being reasonably easy to play. It does require knowledge of those universal mechanics, but while more specific knowledge is helpful, it is often not required.
[1] If you want to read it for yourself I recommend the SF3 an oral history feature from polygon, the topic in question is discussed in the final bit of the interview.