<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4/A</documentType><periodOfReport>2003-12-30</periodOfReport><dateOfOriginalSubmission>2003-12-31</dateOfOriginalSubmission>
    <issuer>
        <issuerCik>0000742278</issuerCik>
        <issuerName>RPC INC</issuerName>
        <issuerTradingSymbol>RES</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001005788</rptOwnerCik>
            <rptOwnerName>ROLLINS GARY W</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O RPC, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>P.O. BOX 647</rptOwnerStreet2>
            <rptOwnerCity>ATLANTA</rptOwnerCity>
            <rptOwnerState>GA</rptOwnerState>
            <rptOwnerZipCode>30301</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>1</isTenPercentOwner><isOther>0</isOther></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeHolding><securityTitle><value>Common Stock $.10 Par Value</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>675282</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeHolding><nonDerivativeHolding><securityTitle><value>Common Stock $.10 Par Value</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>80960</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value><footnoteId id="F1"/><footnoteId id="F2"/></directOrIndirectOwnership><natureOfOwnership><value>Co-Trustee of Trust</value></natureOfOwnership></ownershipNature></nonDerivativeHolding><nonDerivativeTransaction><securityTitle><value>Common Stock $.10 Par Value</value></securityTitle><transactionDate><value>2003-10-10</value></transactionDate><transactionCoding><transactionFormType>5</transactionFormType><transactionCode>J</transactionCode><equitySwapInvolved>0</equitySwapInvolved><footnoteId id="F4"/></transactionCoding><transactionAmounts><transactionShares><value>75600</value></transactionShares><transactionPricePerShare><footnoteId id="F3"/></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>17048292</value><footnoteId id="F5"/></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value><footnoteId id="F4"/></directOrIndirectOwnership><natureOfOwnership><value>RFPS Management Co. II, L.P.</value></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeTransaction><securityTitle><value>Common Stock $.10 Par Value</value></securityTitle><transactionDate><value>2003-12-30</value></transactionDate><transactionCoding><transactionFormType>5</transactionFormType><transactionCode>G</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>27762</value></transactionShares><transactionPricePerShare><footnoteId id="F3"/></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>27762</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value><footnoteId id="F2"/></directOrIndirectOwnership><natureOfOwnership><value>Cust./Guardian Trustee of Trusts</value></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeHolding><securityTitle><value>Common Stock $.10 Par Value</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>60004</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value><footnoteId id="F2"/></directOrIndirectOwnership><natureOfOwnership><value>By Spouse</value></natureOfOwnership></ownershipNature></nonDerivativeHolding></nonDerivativeTable><footnotes><footnote id="F1">Stock in two trusts of which Mr. Rollins is Co-Trustee and as to which he shares voting and investment power.</footnote><footnote id="F2">Disclaims any beneficial interest</footnote><footnote id="F3">Not applicable.</footnote><footnote id="F4">On October 10, 2003, O. Wayne Rollins, II contributed 75,600 shares to RFPS Management Company II, L.P. No consideration was given for the shares. The reporting person disclaims beneficial ownership of the reported securities except to the extent of his pecuniary interest therein.</footnote><footnote id="F5">The prior filing inadvertently listed the no. of shares as 16,972,692.</footnote></footnotes><remarks/><ownerSignature><signatureName>Glenn P. Grove, Jr., as attorney-in-fact for Gary W. Rollins</signatureName><signatureDate>2004-01-14</signatureDate></ownerSignature></ownershipDocument>

