| name-of-the-game(adjective, important, essential, critical, basic) |
| name of game(noun, expression, adjective, idiom, significant) |
| needed(adjective, important, significant, essential, critical) |
| needful(adjective, significant, original, essential, basic) |
| nitty-gritty(noun, adjective, important, original, essential) |
| original(adjective, important, significant, basic, vital) |
| paramount(adjective, important, significant, original, essential) |
| prerequisite(adjective, important, significant, essential, critical) |
| primary(adjective, important, significant, original, essential) |
| prime(adjective, important, significant, original, essential) |
| primitive(adjective, important, significant, original, essential) |
| primordial(adjective, important, significant, original, basic) |
| principal(adjective, important, significant, original, essential) |
| quintessential(adjective, significant, essential, basic, vital) |
| radical(adjective, important, significant, original, essential) |
| required(adjective, important, significant, essential, critical) |
| rudimentary(adjective, important, significant, original, basic) |
| significant(adjective, important, original, essential, critical) |
| specified(adjective, significant, essential, basic, vital) |
| structural(adjective, important, significant, original, basic) |