Fishing

The character is skilled in the art of fishing, be it with hook and line, net, or spear. Each hour the character spends fishing, roll a proficiency check. If the roll is failed, no fish are caught that hour. Otherwise, a hook and line or a spear will land fish equal to the difference between the die roll and the character's Wisdom score. A net will catch three times this amount.

Of course, no fish can be caught where no fish are found. On the other hand, some areas teem with fish, such as a river or pool during spawning season. The DM may modify the results according to the situation.

Paladins

A paladin whose ethos demands reverence for life in all forms should refrain from fishing for recreation. However, he may still fish for food.

[Player's Handbook]
[Complete Paladin's Handbook]