Pieces are placed randomly at the start. Improvise from move one.
All Random keeps the same 8x8 board and the same 16 pieces per side as standard chess, but reshuffles each side's army: piece types and their starting squares are randomly redrawn across your two home ranks, so you might open with several queens and no rooks, or vice versa — only the king keeps its usual square. Once play begins, ordinary movement, capture, check and checkmate rules apply, but memorized opening theory is useless, since every match forces you to build a strategy from the very first move.