Some key rules, looking over the official rule list:
2.7 Demos
Match participants are required to record first-person point-of-view ("POV") demos of all league matches.
Players found not to be recording with the above specifications may result in a match overturn, and/or suspension of offending player(s).
Players must record a separate demo for EACH MAP of play (including separate recordings for any possible overtimes). Players found to be recording 1 demo for the entire match will risk suspension. Recording one demo for all overtime maps (total of 2 rounds) is permitted if no one has dropped or there is no delay at the halftime.
Demos (and Screenshots) must be kept for the duration of the season + the duration of tha playoffs for teams who did NOT make it to playoffs. For teams that make it to playoffs, you are required to hold onto your demos for a minimum of 4 weeks after the completion of the playoffs. In the event of a dispute, a player will be required to upload said demos. Failure to upload all required demos in the event of a dispute will result in a match overturn (or part there of), and suspension of offending player(s). Longer suspensions may be used for repeat offenders of this rule.
3.7 In-match Techniques
a.)Closets are LEGAL so long as they are not physically impossible for tanks or infected players to reach. Some examples of ILLEGAL areas include the vents behind the 28th floor elevator on No Mercy 4, and hiding under the ramp during No Mercy 5.
b.)Blocking the path of the Survivors. It is not legal to block the main paths with bashable objects (cars, logs, forklifts, ladders,etc.) as infected. In general, anything that physically prevents survivors from finishing the round is considered illegal. Also, waiting with the tank above the sewer exit just outside the safe room at the end of No Mercy 3 and hitting a car as survivors come up is illegal. To clarify, if they come up and within a few seconds get hit by a car when there is no reasonable possibility for avoiding it, it is illegal. However, if all the survivors climb up and move around, then it is legal to use cars or garbage cans. CAL reserves the final say on this and all rules governing illegal behavior.
c.)Quick Bashing. Using the weapon switch key (default Q) to change weapons while spamming the bash key is not legal. This results in faster than intended bashing. Spamming bash without switching weapons, however, is legal.
d.) Map Exploits. The use of any of the following exploits in an official CAL match will result in the forfeiture of that round as well as one additional round by the offending team. In all cases, the league will make final determination on whether something is an exploit. Bashing the minigun repeatedly then jumping on it to get a "super" jump is considered an exploit.Skipping any crescendo event where the survivors activate something and a horde is called is not legal. One example is bashing down the door on No Mercy 3 instead of activating the lift.
Reaching map areas through the clipping of walls, floors, roofs, and/or any other normal perimeters is not legal. Using an acquired position to view areas through or over such perimeters is also not legal. Exploitative map behavior may result in the forfeiture of rounds, a match overturn, and/or suspension of offending player(s).
e.)Spectate. At no time while a match is "Live" is a player allowed to join spectate.
f.)Infected Spawn Glitch.Any method to circumvent the mandatory wait time between infected spawns is not legal.
4.4 Ringers
Under no circumstances may a player not on a competing team's CAL roster play for said team in a match. If an opposing team is using a ringer, the match will not go live. Should a team be unable to field 4 players on its CAL roster within 15 minutes of the scheduled match time, the opposing team may file a forfeit win.
5.1 Anti-Cheat
No 3rd-party software is to be installed on servers used in CAL match play. CAL takes no responsibility for the use of any 3rd-party software. Should a match be compromised due to the presence of such 3rd-party software, the hosting team will be held responsible.
a.)ACS Client. All players are required to run the latest version of the ACS client in every match. The ACS client must be loaded BEFORE you start your game (L4D) executable. Any match in which a player fails to comply with this will be overturned in favor of the opposing team and the player(s) will be suspended for two (2) months. The ACS client can be found in the "Anti-Cheat System" section of the website after logging in and choosing a Left 4 Dead division. Instructions for how to run it can be found in the readme that is enclosed with the client itself.
5.2 Server Usage
CAL does not provide servers for matches. Teams are required to provide servers for their matches. Teams may utilize their own dedicated (non listen) server as long as it falls within the ping imbalance rules (see section 5.50). Please note that ANY and ALL issues arising from server problems will be the sole responsibility of the hosting team. This includes, but is not limited to, issues such as incorrect passwords, server reboots, and non-players joining the server. If neither team can obtain a server to play the match before the reporting deadline, both teams will receive a forfeit loss. It is strongly recommended to test/ping your opponents server ahead of time to see if any possible server issues may arise. In the event of a non-player joining the server, an rcon status screenshot will be required so that the offending player can be traced.
