Solutions :

3-letter words (1 point): 26

EEL; ERN; ERR; IRE; LEE; LEI; LEU; LIE; LIN; MEN; MET; NET; NIE; NIL; NUR; REE; REI; REM; REN; RET; RIN; RUE; RUN; TEN; URE; URN.

4-letter words (1 point): 29

CIEL; CINE; CIRE; EINE; ERIC; ERNE; IURE; LEER; LEIR; LIER; LIEU; LINE; LIRE; MERI; NURR; REEL; REIN; RIEL; RILE; RINE; RUER; RUIN; TERM; TERN; TREE; TRIE; TRIN; TRUE; URIC.

5-letter words (2 points): 15

CLINE; INCLE; INERM; INERT; INRUN; LINER; MERIL; METRE; RELIC; RELIE; TRIER; TRINE; TRUER; UREIC; URINE.

6-letter words (3 points): 8

ETRIER; LIERNE; METRIC; RELINE; RETREE; RUINER; UNREEL; UNREIN.

7-letter words (7 points): 2

MERRIER; TERRIER.