One of the dead horses we kick around on this website is that of removal in casual MTG play. The reason for this is simple, nobody wants to lose to a second turn bitter blossom because they don' have a naturalize, pyroclasm, or infest handy. Same goes with a monster creature. Say your opponent uses devoted druid to get out a turn three deus of calamity and is attacking you for 6 damage each turn. All the while your land total is shrinking with no end in sight. Basically its never fun to lose because of one card.
Wizards of the Coast knows this. They've been producing clever ways to rid yourself of pests since 1992. The tricky thing is finding which ones to use and using them properly. Lets look at some of the best ways to incorporate removal into your decks. You may be surprised to learn what some of the colors bring to the table.
First up, creature removal. The most common and necessary. That is likely why you can find solid creature removal with every color. Black and White dominate this field, but Blue and Red have options, and Green has a few too. The best thing when looking for creature removal is cost. Cheaper the better, with any color. If your opponent just spent 8 mana on a scaled wurm, spending only two for a terror gives you all that much more advantage. Some cheap removal cards for every color include: condemn, last gasp, pongify, spitting earth, and lignify. (In fact green has been gifted with quite a few lately.) If you're facing token decks try leyline of singularity and throw a mammoth wrench in their works.
Next we need to deal with artifacts and enchantments, and unless you plan on using one of the worst cards ever, we'll be counting black out of this group. Blue has universal permission spells so take advantage of that. If you miss your chance there is always the option to bounce an expensive enchantment before it does any harm. No color destroys artifacts with Red's zest, but the color can't deal with enchantments. Thus if you really want to be serious, you better splash some white and green. If only to use naturalize/disenchant. A word of caution, you may face decks without a single artifact/enchantment spell. So be sure to limit your removal cards here just in case.
Finally, to keep the contemporary kids happy lets get rid of some Planeswalkers. Not an easy task, but a possible one. It would be pretty sweet to blow your enemies away with a well-timed violent ultimatum, however a good bounce spell can do the trick for a measly two mana. And there's a reason WotC included oblivion ring in both Lorwyn and Alara sets. For a more permanent solution you may want to go with engineered explosives, oblation, or culling scales.
Now that you have a good idea what removal spells are possible its time to make your deck. Unless you have a removal theme going you won't want more than eight to ten removal cards. Any more than that and you may be sitting with two extra crib swaps in your hand at teh end of a game. When deciding what colors to play you should consider how each deals with threats. Mixing two or three with opposite strengths will result in a more dynamic deck. Lastly when using these cards make sure they are being used wisely. Timely removal is the key to any strategy and threat recognition is key to timely removal. Write that down.
The biggest naysayers of spot removal claim that too many of these cards end up as useless filler in your hand. Is that true? Most tournament winning decks use removal sparingly. So there is some evidence to back that theory. That is fine in a two-out-of-three environment that allows you to add removal from a sideboard. Not so much when you sit down for a pick-up game with a buddy. Trust me, you'll be glad you did when you're days of losing to one permanent are behind you.
Update: Hours after posting this article, MTG.com released the latest conflux card: Path to Exile along with this article. Its not for me to say whom is reading whom's mind but needless to say - we are on the same wavelength.