Instructions:Simply buy anything in-store at WHSmith.
WHSmith's current promotion is, spend in-store until 29 March and it'll give you four 2for1 theme park entry vouchers that can be used right across the summer, until 31 October. Better still, there's no minimum spend so buying a newspaper or a packet of chewing gum still entitles you to the coupons.
The vouchers can be used when buying a full price adult ticket on the day (not online), enabling another adult or a child free entry.
Vouchers are valid at, Alton Towers Resort, Legoland Windsor, Thorpe Park, Madame Tussauds, Chessington World of Adventures, Warwick Castle, The Dungeons, Sea-Life Centres and Sea-Life Sancturies.
The vouchers are valid until Saturday 31 October but beware, for different theme parks there are specific dates excluded. Always check on the back of the voucher and on the Merlin website before you go.
An adult ticket for Alton Towers on the day is £36, however web tickets are cheaper; two there are £58. With this deal you have to buy on the day so you'll pay £36 for two. Prices vary at other theme parks.