A draw is not a failure of the rules; it is a result with its own techniques. Players who understand the draw rules save games they should lose and, just as importantly, avoid throwing away games they should win.
Stalemate
The side to move has no legal move and is not in check. The game is drawn immediately, no matter how much material is on the board. A player with a queen and two rooks against a bare king can stalemate and score half a point.
For the defender this is the great resource. If you are hopelessly behind, give away your remaining pieces and aim for a position where your king has nowhere to go. For the attacker, the rule is simple: with a big lead, always leave the enemy king one square, or give check.
Insufficient material
If neither side can possibly force mate, the game is drawn on the spot. The clear cases are king against king, king and bishop against king, and king and knight against king. Two knights against a bare king cannot force mate either, though it is not always adjudicated automatically because mate is possible with cooperation.
The practical upshot: if you are losing, trading down to one minor piece each is a legitimate plan. If you are winning, do not trade your last pawn for nothing.
Threefold repetition
If the same position occurs three times — same pieces on the same squares, same side to move, same castling and en passant rights — either player may claim a draw. The repetitions do not have to be consecutive.
The most common form is perpetual check: a queen checks a king that cannot escape, the king shuffles between two squares, and the position repeats. It is the standard way to save an otherwise lost game, and it is worth looking for whenever you are material down but your queen is active near the enemy king.
Perpetual check is a plan, not an accident
If you are losing badly, stop trying to win. Ask instead whether your queen can reach a square where the enemy king has exactly two flight squares and nothing to block with.
The fifty-move rule
If fifty moves pass for each side with no pawn move and no capture, the game is drawn on claim. It exists to stop a player shuffling forever in a position they cannot win, and it matters in long technical endgames where the attacking side must make progress to keep the win alive.
The counter resets on every capture and every pawn move, so in practice it only comes up in piece endings. If you are defending one, counting matters.
Agreement
In over-the-board chess players may simply agree a draw. There is no equivalent against a computer, and it is worth noting that offering draws in equal-looking positions is a habit that slows improvement — many of those positions still have plenty of play in them.
Dead position
A less-used rule: if no sequence of legal moves could ever lead to checkmate for either side, the game is drawn immediately. Blocked pawn positions with only kings and same-colour bishops sometimes qualify. In practice this rarely needs to be invoked, because insufficient material or the fifty-move rule gets there first.
How the board here handles draws
Stalemate, threefold repetition, insufficient material and the fifty-move rule are all detected automatically and announced in the status line. You do not need to claim anything. If a game ends and you are not sure why, the status message names the specific rule that applied.
Drawing as a skill
Good defenders think about the draw rules from the moment they are worse, not once they are lost. That means noticing early whether the position is heading for opposite-coloured bishops, whether a perpetual is available, and whether trading into a known drawn endgame is possible. Half a point saved counts exactly as much as half a point won.