The Arrow tile lets you freely mark any number on your cards on the line above the Arrow tile.

The Joker tile lets you freely mark one number one any of your Cards.

Use your Jokers and Arrows wisely! If you are aiming to fill a card quickly and you get a Joker, don't use it to fill a vertical line if there are other vertical lines left with more than one open position. If you fill a line with a Joker and later get an Arrow for that same line, your Arrow will be wasted.