Here's the breakdown:
* "On the Field" effects are generally continuous effects that apply as long as the card is on the field. They can be triggered by various events, such as a monster being summoned, a card being activated, or a specific condition being met.
* "Unaffected by..." effects are monster effects that make the monster immune to a specific type of effect or influence. Examples include "Unaffected by Spell Cards" or "Not affected by monster effects."
Here's the key point:
* "On the field" effects DO NOT negate effects that state "unaffected by...".
Example:
* You control a monster with the effect: "This card is unaffected by monster effects."
* Your opponent controls a monster with the effect: "When this monster is Normal Summoned, destroy all monsters on the field."
The opponent's monster's effect will NOT be negated by the "unaffected by monster effects" effect. The "unaffected by monster effects" effect only protects the monster from direct effects that target it. It does not prevent the opponent's monster's effect from affecting the entire field, including other monsters.
Key exceptions:
* Some monster effects specify a type of effect that includes "on the field" effects. For example, a monster might say "Unaffected by continuous effects." In such cases, the "on the field" effect would be negated.
* Some "on the field" effects have specific wording that can override "unaffected by..." effects. For example, a card might say "negate the effects of all monsters on the field."
In summary:
"On the field" effects generally do not negate monster effects that say "unaffected by..." or "not affected by..." unless specifically stated otherwise.
Always refer to the specific card text to determine how effects interact.