When I unpacked my box of Word Factory during the first evening of our company offsite, there was an understandable amount of consternation that went around. Word Factory, you see, is a variation of Parker Brothers' Boggle played on a 5-by-5 grid... and it's slightly more difficult than the original, by virtue of the fact that it disallows three-letter words. Seeing that I was both a wordsmith by trade (and the owner of the game, besides that), there was little in the way of encouragement for potential players.
I had come prepared for such a reaction, though: At that point, I offered to give myself a handicap. While everyone could busy themselves trying to find words of four or more letters within the three-minute time limit, I would hobble myself with a five-letter minimum. Fortunately, this sounded like a welcome enough prospect to people -- at least, enough so that four of us could play a tentative first round.
By the time we got back on the bus the next day, word of the strange handicap had spread. I was actually still winning a few games despite the vocabulary limitations, so much that my opponents had tacked on an extra five-point penalty to weigh me down further. In the meantime, I was having fun -- the heightened difficulty level made the game more interesting for me, and the fact that I wasn't rushing to write down a lot of four-letter words meant that I could hunt for eight-letter specimens across the grid.
It strikes me that a lot of board games can be handicapped in this way; in a sense, this can open the possibility of some very nice evenings between kids and adults. My Word Factory experience particularly noted that there are multiple ways to handicap stronger players. Apart from allowing more people to get into the game, it also made for a few spectators who cheered at every seven-letter word that I was able to find.
Any game that relies on winning a certain amount of points, for example, can be adjusted to give weaker players a head start. This could have involved, say, three "free" points to all my Word Factory opponents. Similarly, a two-on-two basketball game can easily start from a 5-0 score to benefit the weaker team, and novice Scrabble players would probably rejoice at a 20-point windfall. I can't imagine a better beneficiary than Texas Hold'em Poker here, though, seeing that its chips are actually a fixed number of points distributed across an even number of players. Anyone willing to grant the smaller people a few more chips at the expense of the card sharks should be able to adjust the game to their liking.
Alternatively, there's also the possibility of kneecapping the strongest player on the table. This was how we executed the Word Factory experiment, and we apparently went about it in two different ways. The first approach was to alter or restrict a gameplay rule for higher difficulty; the second was to force a starting penalty in points. "Kneecapping" probably works best in multiplayer games where one dominant player often faces down a group of weaker opponents, and prevents everybody from having to train their guns on him just to get a decent chance at winning.
I find resource denial to be one of the best ways to force a disadvantage. Many games use or track currency of some sort, and reducing this amount at the start of a game will force experienced players to think differently. An expert Monopoly player with only $1200 out of his expected $1500 would have to adjust her style of play, for example, while a Risk player who has five less armies may have to create a whole new strategy just to survive. While chess would normally be difficult to handicap in this regard, you can impose handicaps in competitive play by limiting the amount of time on a particular contestant's clock.
Finally, there's also the question of adding new rules or conditions to accommodate different skill levels. Quite a few Magic: the Gathering handicaps, for example, involve imposing additional "standards" on more powerful players during deck contruction. Maybe they can't play with cards beyond a certain rarity or expansion set. Maybe they can't play with more than one or two copies of each card. Maybe they maintain a reduced hand size or a larger deck. This, as you can imagine, is probably the only logical option for games with a high degree of customizability, or multiple ways to win -- it would normally be too complex to cover all the possible avenues of advantage otherwise.
This is not to say that any game can be handicapped, though. Tic-Tac-Toe is probably the simplest example that I can think of -- the closest we can get involves allowing weaker players to go first, and even then, that's not much of a handicap to the highly skilled people. Clue (Cluedo) is a more subtle example, seeing as any effort to grant weaker players an advantage might severely throw off the pace and balance of the game. I feel that games that reward personal skills without being based on points (endurance running and Pictionary, for example) are extremely difficult to handicap without compromising the skills involved -- a good handicap should play to the advantages of the stranger player/s.
On my side, I'll probably try to negotiate something for our Word Factory sessions. I'm thinking that the five-point penalty is a little restrictive -- three points may be just about right, considering that I should need only the equivalent of one or two more words in order to catch up. Maybe that way, I can convince them to offer me a three-point head start the next time we stop by the nearest badminton court. :)