When considering an online casino bonus there are some terms which you need to understand to avoid disappointment at not receiving what you may have expected. A bonus in an online casino is usually offered as either a matching deposit bonus or an opt in bonus; the last one is often associated with a leader board competition or a cash back offer or indeed a free cash bonus and all you have to do is register; a matching deposit on the other hand requires some cash to be deposited by you the player. The most common form of matching deposit bonus is for new players to a particular online casino although there are also special offers around for a casino bonus for existing players if for example a new game is released or like now it is around a special holiday period. The matching deposit bonus takes the form of a percentage of your deposit being added to your account to play with but it cannot be immediately withdrawn; the most common percentages are either 100% or 50% and the cash is probably added to what is known as your bonus account and in order to withdraw it you must meet certain requirements known as play through. When taking a casino bonus you should read the terms and conditions as these will give you a clearer picture of what the play through requirements are; it will be expressed as a certain number of times that your casino bonus must be staked before it can be withdrawn and sometimes also as the number of times that your bonus plus your deposit must be staked. You should also watch out for the fact that not all casino games count towards the staking requirement or at least not for the same percentage. Stakes on slots will generally count 100% towards the requirement but it is not unusual for casino games such as roulette not to count at all or for a small percentage such as 5%. If you play roulette therefore you will need to stake 20 times as much as you would have to on slots to achieve the same staking requirement. Online casino bonuses are great buut make sure you know what the rules are to avoid disappointment..