Why is it that if you have no legal moves to play the game ends in a draw?

Because it's considered a stalemate.
A draw is when both players win. A stalemate is when no one wins.

If your opponent is not in check and cannot legally make a move, it is impossible for you to checkmate them. Since no more moves are possible, the game stops with no winner.

I would really like to answer, however, @snoozyman has probably said it best. I do think that the results should be based on each players remaining material, though. For example if you had a pawn, you'd get +1 rating, bishop and knight +3, rook +5, queen, +10 and so on. I think that'd be pretty cool. But who cares, right?

it meenz yuuz ned to praktis matin’
pruuvz it on da bord
Well said, however, better grammar next time please!


because that's one of the rules of chess. It causes you to be "on the lookout" to NOT put your opponent in that position & possibly draw a game which might've been winable. On the other hand, if you're losing a game, sometimes you can entice your opponent to put you in such a spot since a draw is still better than a loss.
draw = stalemate = tie

Stalemate like the North vs South Korea War

The other kind of stalemate is when one side has overwhelming material superiority, but because of the position, cannot achieve victory... like a siege. The mistake was to allow the weaker opponent to get into a position where no further progress could be made. The side besieging doesn’t win just because it had a bigger army. You actually have to either force your opponent to concede or defeat them outright.

Because if your opponent has no legal moves the game can't continue. That's not considered as a checkmate as the king has to be checked before he's checkmate. Since your opponent isn't in check, and there are no legal moves for him, the game is over.
One of the main objects of the stalemate rule is to require the "winning" side to play with care and precision. Even is you're a rook and bishop ahead, if you start just pushing any old piece, thinking "I'm bored, let me just play anything!" you may find yourself screaming "I hate that stupid rule!"

To be fair, if you are new to chess, stalemate can come as a very unpleasant surprise! I say, lets try to be patient and welcoming to these newcomers. We can always call them names six months from now!
Stalemate being a draw is a rule of chess. It does make sense in that, based another rule, you cant move a king into check. The game clearly finishes but you could alternatively declare the statemated player the looser since they have “failed” to be left with any valid moves, it does have alternative logic. However I don’t think it would be a good idea to change to that. The possibility of stalemate gives extra strategic depth. Chance for an overwhelmed player still to find a result A whole load of KP drawn end games would now becomes wins, do even more small pawn advantages become wins, which would make material even more key and not quite so interesting
Yes, it makes sense, but it doesn't make obvious sense! That's why it can come as such a surprise to a newer player. That's why it's worth spending a bit of time explaining it instead of just saying "It's stalemate, stupid!"

Apart from that, some endgames would be simpler without stalemate. King and pawn vs king would be always winning because opposition wouldn't matter. You would be able to either promote or force a stalemate to win.
There are other examples as well. For instance that queen vs bishop pawn on the 7th rank where defending side has to know about stalemate trick to draw the game. I am sure there are plenty other examples.
I think that's rather silly. If the game is in a state where my opponent can't make any legal moves, he should lose. Why does it end in a draw?