Rules Technicalities

Doesn't there have to be at least two dartboards available for a league match?
No. Only one board is legally required except in playoffs.
Can a player stand to the left or right beyond the end of the toeline while throwing as long as they are still behind the line?
Yes, as long as they don't interfere with a player in another lane. The toeline is assumed to extend to infinity in both directions.
Can a player step over the toeline as they are throwing as long as the dart leaves their hand before their foot touches the floor?
No. This is a toeline violation. If this were legal, then so would be jumping over the line and throwing your dart in the board as long as you were airborne! Granted, this might not be easy or accurate, but no one would interpret the rule that way. Both feet must be behind the line until the dart leaves your hand - on the floor or in the air.
Sometimes before a match, the boards are all filled with people playing games and I can't get in enough warmup time. Is there anything I can do?
Yes. The boards to be used for the match are to be cleared of games at least 30 minutes before the match and left open for everyone to warm up (Rule 2(i)).
Can a player hold their darts in the board while they are marking their score?
Maybe. Again from Rule 3(c):

"A player may walk to the board to see what his/her dart has scored, but he/she may not touch the dart. Once the player touches a dart in the board, his/her turn ends. Score for that dart and a previously thrown dart is counted."

This rule has been interpreted by many to mean that it is legal to hold your darts in the board while you mark your score since your turn is over anyway. There's never been a protest over it though and that is how these things usually get settled once and for all.
If a player drops a dart and it falls on the floor across the toeline, does that count as a throw?
A throw is a throw and a drop is a drop. "Throwing" the dart implies some deliberate motion and intent. It's not so important where the dart hits - if the dart flew backwards out of your hand while you were in the act of throwing it would still count, but accidentally dropping the dart - no matter where it lands - couldn't be considered a throw under any circumstance that I can imagine.
If a player busts on their first dart but continues to throw their last darts, isn't that "practicing during a game" and a violation of Rule 4(i)?
Technically, yes, but few people object to such things except maybe during playoffs. You are within your rights to do so, however.
An opposing Captain wrote down only one player at a time for singles even though there were four boards available. Is that legal?
Again, technically, yes, but few people do such things except during playoffs or near the end of the season in a tight race. If the other Captain insists on playing games one at a time, however, there is nothing you can do but play them one at a time and WIN!
During a singles match, a player on the other team had a friend (not on the team) practically standing on the line with them telling them what to throw at with every dart. My player lost because of this. Is that legal?
Coaching is permitted. Period. As long as the person doing the coaching does not disturb your player at the line and clears the area when it's their turn, it is entirely legal. The player still has to hit what they're throwing at!
During a Spanish game, the Captains had agreed to play "Gentlemen's Call" so that we wouldn't need to call every shot as long as we went "in order" from 20's to 19's etc. Their first player closed 20's with their first dart and continued to throw at 20's for points instead of going on to 19's. Should those points have counted?
What you are talking about is actually not "Gentlemen's Call". Spanish is a "call" game. If the captains agree on some method of throwing without a verbal call, then the teams must abide by that. In this case, the Captains should have agreed in advance what to do in a point situation. There is no rule to cover it.

True "Gentlemen's Call" is where the teams are ON THEIR HONOR. This means they TRUST each other not to mark anything that they were not actually throwing at ("in order" or not)! If you don't TRUST your opponent that much, then don't play "Gentlemen's Call". Verbally call every shot. Then, the player MUST continue to throw at 20's (in this case) until they call something else. So, in either of these cases, the points would have counted.
Can I refuse to play on a non-sanctioned dartboard?
Yes. In fact, the league encourages you to do just that! That is the only way that we have of enforcing the sanctions. Remember, however, that only one dartboard is legally required for a match, so if the bar has another board that displays a sanction card, then you must play the match on that board. If the bar has no sanctioned boards available, then the visiting Captain may insist that the match be moved to a neutral location that has sanctioned boards available. You should make every attempt to contact a Board Member immediately to notify them of the change.
Can I refuse to play on a sanctioned dartboard if I think it is not up to standard in some way?
No. You may play the match under protest (clearly indicate this on the scoresheet with a signed note and enclose the $10 protest bond). If you do not wish to go that far, at least note it on the scoresheet, or call a Board Member, and the Sergeant At Arms will reinspect the board as soon as possible.
Can I use soft-tip darts in a league match?
Yes and no. The SCDL Rules never even mention the dart itself. ADO Tournament Rules state that the dart must be "less than 12 inches in length" and weigh "less than 50 grams", though even there, they don't specify metal tips. So, as far as the league is concerned, soft-tip darts are legal.

On the other hand, some bar owners may object because many feel that soft-tip darts will harm a bristle board. The Board of Directors has ruled that league members must abide by the wishes of the bar owner. So in this case, soft-tip darts may not be used.
A great question and answer originally posted on the "alt.sport.darts" newsgroup:

This happened twice this season. On the third dart, the dart deflected off the flight of one of the darts already in the board and landed balanced between the two darts already stuck in the board. The first time, the point wasn't touching the board so we decided "no score".

The second time the same thing happened, but the point ended up under the wire between two numbers. The point wasn't stuck in the board, but was touching the surface of the board.

Do you score with that dart? And if you do score, which number do you score -- the one where the point is touching or the number where most of the dart is lying?

Both times we called "no score" with that dart. But I would like to know what the correct call would be if this fluke ever happens again. I've been playing for 13 years and I have never seen this happen before.
You were right in the first case. If the POINT is not touching then the dart does not score.

In the second case, the point is touching -- therefore it will score. As to the value, the dart is worth the point value of the wedge it is in (eg., the dart enters in the 20 but the point goes under the wire into the 1 so it is worth 20 points). This also applies to single, doubles and triples as well.

Note: SCDL Rule 3(e) says:

"The dart shall be scored where the point of the dart first penetrates the board. A dart may only be scored if the point of the dart is penetrating the board."

So the above answer is not strictly correct by our rules because the word "penetrating" is used instead of "touching". However, if the point is penetrating the board even slightly then the above answer would apply.