Fighting with no rules, shot untrained revolutionary by a lake (5,3)

'fighting with no rules' is the definition.
'total war' can be an answer for 'fighting' (thesaurus). I am unsure of the 'with no rules' bit.

'shot untrained revolutionary by a lake' is the wordplay.
'shot' becomes 'tot' (I've seen this in other clues).
'untrained' becomes 'raw' (I've seen this in another clue).
'revolutionary' says the letters should be written in reverse (letters revolve around).
'by' says to put letters next to each other.
'lake' becomes 'L' (geographical abbreviation).
'raw' reversed gives 'war'.
'a'+'l'='al'
'war' after 'al' is 'alwar'.
'tot'+'alwar'='TOTAL WAR'

Can you help me to learn more?