S4 League plays similarly to other online Korean and now English games of its nature, such as GunZ and eXteel; however it is somewhat unusual in its particular emphasis on teamwork, and sports, rather than violence aligned perspectives. It is a third person shooter, with three modes of play: Touchdown, Deathmatch, and Chaser; all of with either no limits, or sword-only that restricts users to melee weapons and limited skills.

Players must have one weapon and one skill equipped in order to play.

Touchdown operates similarly to Capture the Flag, in which two goals are set up on either side of a field. A "Fumbi", which represents a ball of sorts, is placed in the middle. A player must grab the Fumbi and take it to the opposite team's goal in order to score a Touchdown. The Fumbi also quickly drains the SP of the player holding it, which can result in the use of skills being disabled until the Fumbi is dropped or the character dies. Passing through a gate of falling off the map will "reset" the Fumbi, which returns it to the starting position.

Team Death match places up to 6 people on each team, and has the player fight for a set amount of points, or until the time runs out. Death Match fields are characterized by having many destructible objects in the game environment, such as roof-breaking of buildings and crates scattered strategically around the field.

Chaser Mode is an experience similar to survival, as if the survivors are being "hunted". One player is chosen randomly to become the Chaser, who is indicated by a Grim Reaper hovering near him. The Chasers objective is to dominate the survivors in the given time, or survive if the survivors are too powerful, which is unlikely since the Chaser receives a huge attack and defense bonus, and reload time is shortened. The Chaser is also limited, since the Grim Reaper is blocking part of the visible area, and the survivors are outlined in red and black from his/her eyes. The players who are not chosen as the Chaser are the survivors. Their objective is to either kill the Chaser or survive in the time given. When enough attack power is implied on the Chaser,measured by a bar, the player receives 2 bonus points. While in a round, the player who is in 1st place and is not the Chaser is the "Target". The Target will always have visible cross-hairs which can be seen as long as the target is in your viewing screen. If the Target is killed, the Chaser receives double points and the next player on the ranking list is the Target as long as he/she's alive. There are also damage rankings, which are awarded to players if they either harm the Chaser enough with ranged or close-ranged weapons. Damage rankings give off bonus EXP.

Sword mode match is a type of game where people can only use melee weapons. This style of game-play, as the name suggests, prohibits ranged weapons to be used.

Also a feature called the Combi system exists. The Combi system focuses on teamwork. Grouping up and playing with people with this system and playing in the same room as them gives the player a boost in EXP.

There is also a student-teacher concept where a level 13+ player is called a "Combi Master" and is treated as a teacher towards the "student" player.

There are many weapons and skills in S4 League that diversify play styles. All weapons and skills offer a "license" which allow a player to test a weapon or skill for 5 hours. Licenses may only be obtained once. Afterwards, the player can do tutorials for each weapon which is essentially the license test again but without the ability to test a weapon.

Weapons can cause criticals which increase the damage done per hit. Short range and Long range weapons gain criticals by performing Head shots, which is generally aiming for the head of the avatar. Mind type weapons, specifically the Mind Energy and Mind Shock, gain criticals when the user and the target are on the same elevation.

Along with weapons and skills, S4 sports a large selection of clothing items including shirts, head decorations, pants, shoes, and gloves. All items can be upgraded to give additional bonuses to damage, damage reduction, HP and SP, and other benefits.

There are outfits that resemble characters from the Music Videos of the songs in the DJMAX series (another game franchise made by Pentavision). A male character can buy the costume that makes them look like the gambler from the music video for Out Law, a female character can buy the costume that makes them look like the girl wearing yellow in the opening video for the first DJ Max Portable. Both gender characters can buy NB Ranger Masks (known in S4 as Envy Rangers, due to NB sounding almost like envy).

Items in the shop are usually part of a set but may be mixed and matched freely. Completing a set does not give any additional bonuses. Some items require the player to reach a certain level before using, but also do not give any additional bonuses.

Every piece of clothing must be repaired when its efficiency hits 50%. Repairs are roughly one half of the original purchase price, and increase as efficiency drops. If an item is upgraded, repair prices are doubled. Damage applied to equipment during Touchdown matches are reduced if the player is killed while holding the Fumbi. (Research is being conducted to determine whether or not the damage to equipment in a Touchdown game is GREATER than damage to equipment in a Death Match)

S4 League uses a p2p and p2s2p connection in order for players to play in matches. When a user connects to a match, they become connected to the other players in the match. This isn't a problem for LAN matches or short distanced players, but can cause lag for those who are playing internationally or are on dialup or narrowband connections. In addition, the game disables players with too large of ping from damaging each other. Some people are not visible to the other players as well, causing a problem of not being able to defend and when that person scores a Touch Down, the screen concentrates on the nearest character instead of the TD person. Also, players may ball lag, meaning they cannot see who has the ball, and cannot pick it up either.