Why did your melee monster attack from other position?

For those new players, you might be overwhelmed by the numbers of skills there are in Splinterlands. I feel you too, for someone who started this game in Aug this year. It took me a month to remember the skills and their respective icons.

For start, we all know that Melee monster can only attack from first position. But there are some occasion where melee can attack from other position due to monster abilities or rulesets.

Let me list out with abilities that allows monster to attack from other positions:

#	ABILITIES	ABILITIES IMAGE	DESCRIPTION	HOW IT WORKS
1	OPPORTUNITY		Monsters with the Opportunity ability may attack from any position and will target the enemy Monster with the lowest health	Refer to screenshot 1
2	REACH		Melee attack Monsters with the Reach ability may attack from the second position on the team	Refer to screenshot 2
3	SNEAK		Targets the last Monster on the enemy Team instead of the first Monster	Refer to screenshot 3