Upwords is a board game invented by Elliot Rudell and published by Hasbro Games (a subsidiary of Hasbro). Similar to Scrabble, except that players can stack letters on top of other words to create new words. The higher the stack of letters (up to 5) the more points are scored. This makes words built in later turns of the game often more valuable than earlier words, increasing play intensity. For example, if the word on the board is CATER, a player on a subsequent turn could put a B and E in front of CATER and then put an L on top of the C and a D on top of the R to build BELATED. The game's scoring is well balanced in two senses: (1) players get more points for words if all the letters are on the first board layer, but (2) then they get more points as tiles get higher since you score for the tiles in your word and the tiles under your word.

Since Upwords lacks bonus squares like Scrabble, there have to be extra rules to keep people from capitalizing on other people's words and they do this by disallowing plurals that simply add S as well as other similar rules.

Originally, Upwords was played on an 8×8 square board, which many players felt to be cramped relative to Scrabble's 15×15 grid. Newer Upwords sets come with a 10×10 square board, which allows for much more comfortable play.

There have been national tournaments played in Hungary and Turkey. The game is available in about 20 languages.

Currently Upwords is available as one of four e-games bundled with MSN 6.2 from Microsoft.