Link helper VS typing URL - ruby-on-rails

Question

Something weird is happening and I don't know why.
When I use the helper <%= link_to "New game", new_game_path %>, my new game form does not submit.
But when I acesses the view typing the URL localhost:3000/games/new form works just well
Any idea how to solve that?
Thanks,
Here my rake routes
Prefix Verb URI Pattern Controller#Action
root GET / games#index
user_sessions GET /user_sessions(.:format) user_sessions#index
POST /user_sessions(.:format) user_sessions#create
new_user_session GET /user_sessions/new(.:format) user_sessions#new
edit_user_session GET /user_sessions/:id/edit(.:format) user_sessions#edit
user_session GET /user_sessions/:id(.:format) user_sessions#show
PATCH /user_sessions/:id(.:format) user_sessions#update
PUT /user_sessions/:id(.:format) user_sessions#update
DELETE /user_sessions/:id(.:format) user_sessions#destroy
users GET /users(.:format) users#index
POST /users(.:format) users#create
new_user GET /users/new(.:format) users#new
edit_user GET /users/:id/edit(.:format) users#edit
user GET /users/:id(.:format) users#show
PATCH /users/:id(.:format) users#update
PUT /users/:id(.:format) users#update
DELETE /users/:id(.:format) users#destroy
delete_progress_progresses POST /progresses/delete_progress(.:format) progresses#delete_progress
progresses POST /progresses(.:format) progresses#create
search GET /search(.:format) games#search
game_levels GET /games/:game_id/levels(.:format) levels#index
POST /games/:game_id/levels(.:format) levels#create
new_game_level GET /games/:game_id/levels/new(.:format) levels#new
edit_game_level GET /games/:game_id/levels/:id/edit(.:format) levels#edit
game_level GET /games/:game_id/levels/:id(.:format) levels#show
PATCH /games/:game_id/levels/:id(.:format) levels#update
PUT /games/:game_id/levels/:id(.:format) levels#update
DELETE /games/:game_id/levels/:id(.:format) levels#destroy
insert_levels_game POST /games/:id/insert_levels(.:format) games#insert_levels
games GET /games(.:format) games#index
POST /games(.:format) games#create
new_game GET /games/new(.:format) games#new
edit_game GET /games/:id/edit(.:format) games#edit
game GET /games/:id(.:format) games#show
PATCH /games/:id(.:format) games#update
PUT /games/:id(.:format) games#update
DELETE /games/:id(.:format) games#destroy
login GET /login(.:format) user_sessions#new
logout POST /logout(.:format) user_sessions#destroy
My route file
Rails.application.routes.draw do
root :to => 'games#index'
resources :user_sessions
resources :users
resources :progresses, :only => :create do
collection do
post 'delete_progress'
end
end
get 'search' => 'games#search'
resources :games do
resources :levels
member do
post 'insert_levels'
end
end
get 'login' => 'user_sessions#new', :as => :login
post 'logout' => 'user_sessions#destroy', :as => :logout
end

Answer 1

Sure, you can use string as relative URL. This will never crash since rails will not try to resolve your routes building it. My guess is, that you might have a typo of some sort.
There is no reason why this wouldn't work. I have searched your git app for "new_game_path" but could not find a single example where you use this code.
I have only found < a href="/games/new">New game</a> in your layout.
Replace it with <%= link_to 'New Game', new_game_path %> this works in your app. I have just tested it.
If you intend to use internationalization at some point, you should avoid standard HTML links. They will not keep your locale persistent.

Answer 2

form
You mention that your "form does not submit"
This is not a problem with your link_to - it's an issue with your form; they are two different issues:
--
link_to
link_to takes you to a new page. It's a helper method to help create the equivalent of Your text
This means that if you're sending requests to your new action, it should not matter how the users get there - only how the action is rendered.
The typical case for a form is as follows:
#app/views/games/new.html.erb
<%= form_for #game do |f| %>
<%= f.text_field :attribute %>
<%= f.submit "test" %>
<% end %>
#app/controllers/games_controller.rb
Class GamesController < ApplicationController
def new
#game = Game.new
end
end
--
Fix
When you mention your new game form does not submit, that's an issue with your form itself. This could be due to a number of reasons, but typically with the way in which you're rendering the form
To fix this, you'll need to detail how you're rendering your form & how you'd like it to submit
Update
Having read your updated comments, if the form works when you send the requests to the "naked" url, the issue may not be with the form itself.
As a rule of thumb, you'll always want to use the Rails helpers when defining links etc. In your application layout, I found that you posted "pure" HTML to create a link. This is bad because if the Rails syntax changes, or your routes change, your application won't update correctly.