The necessity or compulsion that will prevent us from experiencing the effects of risk in gambling is to limit money when gambling, as you said, this is clearly true but will only be done by a small percentage of all gamblers. Because the temptation of casinos is so great, sometimes when we are careless we are easily influenced to bet there.
Yes, if we don't want to experience significant losses, we must try this step as best as possible because we will definitely experience the results with great happiness.
Limiting the money to playing gambling is one rule among many other rules that we must have when playing gambling. We must stick to the rules if we don't wants to gets trouble in gambling. Many people already breaks their own rules and can't survive in gambling and becomes addicted to gambling. The temptation of casinos will always be there but if we can stick to our rules, we will not tempted and will enjoy gambling as an entertainment. We can treat gambling as a fun activity and will not used much money because we don't wants to gets trouble. When we losses, we will not try to recover the losses because we knows that can makes us lose more money because that can related to the emotional that can increases.
When some people think of rules, they think of complex and restraining principles which may difficult to apply, but when we talk about rules, we simply mean common sense behaviors which can protect us from taking absurd decisions when we gamble, but even then there is a great deal of gamblers which want to have none of it, as they think they will not obtain the same fun if they follow those rules, a misconception, but one that can prove to be very dangerous for some gamblers.