"If it is icy, you can break something."
Translation:S'il y a du verglas, tu peux te casser quelque chose.
the answer should also be accepted without the 'te'. The sentence doesn't necessarily mean you break yourself, you could break anything.
The implication is that you may be injured (by breaking an arm/leg, for example). So while we may construct scenarios in which one might break something else, the most likely solution is that you will injure yourself. For this reason, the verb is used reflexively.